bÀi tẬp chuyÊn hÓa hỮu cƠ - huỲnh bÉ (nguyÊn vỊnh) 395 pages

8/10/2019 BI TP CHUYN HA HU C - HUNH B (NGUYN VNH) 395 PAGES

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H U N H B ( N G U Y N V N H )

BI TP CHUYN

HA HU CLA CHIMIE ORGNIQUE

(Par les exercises etes problmes)djbdjbcjb. TO

SCH DNG CHO GIO VIN, SINH VIN

I HC V CAO NG CHUYN HA

WWW.FACEBOOK.COM/DAYKEM.QU

WWW.FACEBOOK.COM/BOIDUONGHOAHOCQU

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W.DAYKEMQUYNHON.UCOZ.COM

ng gp PDF bi GV. Nguyn Thanh T


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Li ni u

Ni dung sch bao gm nhng bi ton hu cc tuyn chn t nhiu tliu c gi tr ca nhiu tc gi Php v c nhm li thnh tno ch '

PH N A: I CNG HA HU c

Chng 1: Danh php hu c (Nomenclature)

---------Chng 2: S biu din phn t (Representation des m olecules)

Chng 3: Ha hc lp th (Strochimie)

Chng 4: Nng lng, tnh hnh hc v s phn cc lin kt

(Energi, geometric et polart des liaisons)

Chng 5: S thay th i nhn (Substitution nucleophiles)

Chng 6 : Ph n ng kh (Reactions cTlimimations)

PH N B: TNG QUT V NHM CHC

Chng 7: Ankan (A lcanes)Chng 8: Anken, dien lin hp (Alcnes, dines conugus)

Chng 9: Ankyn (Alcynes)

Chng 10: Dn xut thm aren, tnh thm

(Drivs aromatique: arnes, aromaticit)

Chng 11: Hp cht c - kim (Composes organo - m talique)

Chng 12: Hp cht hiroxyl v dn xut

(Compo ses hyroxyis e t rivs)

Chng 13: Hp cht ccbonyl ha (Com poses carbonyls)

Chng 14: Hp cht cacboxyl ha (Com poses carboxy ls)

Chng 15: Hp cht c nit (Composes azotes)

Chng 16: Hp cht thin nhin (Substances naturelles)

Bn mi nm trc khi cn ngi ging ng i hc, chng ti cthm ao c gi g c c mt cun bi tp Ha hc nghin ng m . V vyhn ai ht chng ti rt hiu s kht sch ca sinh vin. D. khi bin son

tp sch ny chng ti ch c mt c nguyn duy nht l mong mun gip ccbn sinh vin chuyn ngnh Ha hc c thm ti liu nghi n cu v nng caokin thc V d lm vic rt cn trng moiig n s l tai liu c gi tr,

nhng sai st l iu ch c cbn khng th trnh e, chng ti rt mong nhnc s gp xy dng ca cc thy c v ca cc bn sinh vin.

Chn thnh,

N guyn Vnh

3



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PHN A



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a) C bao nhiu gc pentyl? Cho bit tn thng thng.

b) C bao nhiu t-hep ty l (tertioheptyl).

c) Cng eu hi vi cc t-ctyl (tertiooctyl).

a) n-pcntyl: C H 3 -CH2 -C H2-C H2 -C H2-

iso-pentyl: CH3-(pH -CH2-C H2- CH3 -C H2 CH -CH2 -* CH3 CH3

sec-pentyl: CH3 -CH2 -CH2-CH -

CH,

/ ;

neo-pentyl: CH3-C -CH2- vv-K - ,,'' ch3 '7" ,v ' . - " V w

tertio-pentyl (t-pentyl):

CH3 -C H2- c h -

c h 2Xc h 3

b) Tri ti ba te rtio -tiepty l

CH



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CH3X

c h 3 - c h 2- c h 2- c h 2- c h 2-C - h 3

c h 2- c h 3c h 3 - c h 2 - c h 2- c h 2 -C ------------------------------------------- -------

h

. c h 2 - c h 3 , C3H7

CH3-C H2-CH2 - - G H3-C ~ -c h 2 - c h 3 "

Cho b it cng thc khai trin cng ng vi cc hp ch t sau :

a) Dimetyl-4,4 etyl-7 (metyl-2 propyl)6undecant.

b) Vitam in ,= (tr im ety-2,6 ,6 cyclohexen-1 y)-9 dim et I-3,7

nonatetranol-2,4,6,8,1.

c) Dimetyl-1,1 teropentyl-4 cycloheptan.

d) Dimetyl-;1,2 tertbuty 1-4 jbeiizen. : ; ,

e) Metyl-4 etyl6isobutyl- naphtaen.

f) Dimety-2,7 ietyl-9,10 anthreen.

c) Tn ti bn terti-octyl



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/ ; ! : / c -

a) V it cng thc khi trin ca mctyl1 pentylclorua v dimeiy 1- 1,1hexyl corua.

b) V i t crig thc kha i tr in ca tris c]oro-J m cty l-2 propyl-5,5,7undccan.

c) Gi tn ca hp cha't sau nh th no? , .

CH2- CH = CH 2H O s C - CH2- C- CH = CH - CH = CH 2

_ ' n 3H7 \ .

a) C1 - CH - CH 2 - CH2 - C H2 - CH3CH3

/

c h 3C i - C - C H 2 -C H 2 -C H 2 -C H 3

H 3 . . {

b) . 'r H 3C - C H - ^ H - C

c h 3 - g h 2- c h 2- c h 2. C - c h 2- f H - CH2- CH2- c h 2- c h 3

H 3C -


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t *

1.4

Vit cng thc phng v cni Ihc phi cnh tns; ng vi cc dn xulvng c cu sau, v nh scc nh.

---------a) Bieyclo 2.2.1 heptan_________________

b) M ety l6hydroxymetyl8bicyclo[3.2. l]oetan

c) Metyl-7 tricyclo[3.2.2.04'fi]nonan.

1.5

a) Bit rng long no (camphre) c danh php trimetyl-1,7,7 bicyo-[2 .2 . l]hep larton -2 , hy biu din cng thc phn g v cng thc ph i cnh, suy racng thc ca nor-long no (norcamphre), kh hiro-long no

(dehydrocamphre), kh hiro-nor-long no (dehydronrcamphrc), Ngi ta chr rng lin kt i trong sn phm hai vng c cu khng th xu: hin u

cu. .

b) Camphan l cacbua no c hi vong cng ng vi ca mphre . Biu dincng thc c camphaii v nrmphan v cho bit tn h thng ca nhng hdp

cht ny.

in



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a) Long no c th c bicu din hng cnu ihc sau:

Mc

Kh hidro-long no tng ng vi cng thc lon " no kh hiro.Me

;; A ^ C H ,

Z J

Biu din phns Biu din phi cnh

Kh hidro-n-lona: no cng sn phm khng c nhm th.

n 2

fc}:

norcarxiphan:

Bicyclo[2.2.1]heptan

cmphari: trimetyi-1,7,7

bicyclo[2 .2 . ljhep tan

. 1 . 6 .

a) DimetL-3,4 nonenynon-3,5,2.(Hydroxy-2 etyl)-3 hiroxy-4 pentanoic.

c) Metyl-3 etyi-4 N,N-dirietylamino-5 hexnon-2.

d) Cloro-3 melyl-5 hirox :y-6 amino-2 heptan.

e) FomyU3 acetyl-5 he^tnoic.



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*

eft) rffi?CO CO oo

a) CH3 - c - c = c - CH = CH - CH2 - CH, - CH,II I Io Me Me

h) CH3 - (pH - (pH - CH2 - COOH

HO CH2-CH2OHMe Et

c) g h 3 - - CH - CH -


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Me

c) CH, -*c - CH2 - CH - H -' 1 1 1 I

o CO - N H -COOH

CO - NH - C2H5

S 0 2 - CH3d) CH3- (CH2)2 - (pH - (CH2)2 - (JTH - CH2-CH - (CH2)2 - C H2 - NH2

OH___

CH-,___________ __________

_

_____-_ CH = C H -C H 3

c ) * _ / C H 2 -CH2OH Tnkhc:

(hidroxy-2-etyl)-2-cacboxy-3-xicloheptanon

0 CfiHj.- N - NH -C H 3 , Tn khc:

iiie tyl-1,2-phenyl- J -hidrazin

in&marppir-

2 . 1

Biu din nhng phn t sail theo ' S biu din Newman v ly thuchng trc ch nh. . r

a) CH2OH - C H2OH (hnh dung s to chelat bng nhau)

b) C6H5- HOH - H = C H 2

c) Bulyn1 ol-3 (HCsC - CJrtOH -..CH;)

> d) M ev . / O H - C H ,H Me

c) > . - .C H ,- < |

f) ' Mc r l . . . .

: & 3

13



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11/394

h) C H j - C - A . r . C H ,

o o

a) O 'A

Hv j v - H

c) V

n f?H w H

j)

M c s / Me

Metrc 1 v H- 0 trc 2

l r MeMe

a)>/

i)

h) H

H , fc3

o

trc 2 x r

14



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2.2

Biu dicn nhn phn t sau:

a) OH

OHim ni cis

theo phi cnh v s biu din Newman(theo cc trc 1, 2, 3). V trim thi s

chelat ha.

o

o

theo phi cnh v s biu n

Newman (theo cc trc 1, 2, 3).

0

'O

theo pi cnh v s biu dn

Newman (theo cc trc 1,2 ).

theo phi cnh v s biu dinNewman (Ihco cc Irc \ 2).

theo phi cnh v s biu din

Newman (theo cc trc 1, 2).

theo phi cnh v s biu din

Newman (theo cc trc 1, 2).

, McMu

h) ... ' > CHO

1 '>

i)

theo phi cnh v s biu dinNew man (theo cc trc 1, 2).

the s biu din Newman (theotrc 1 ri theo trc 2 ).

Iheo phi cnh v s piell din

Newman (Ihco cc,lrc 1,2^. ,

15



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Iheo phi cnh v s biu dinNewman (theo cc trc 1, 2).

theo phi cnh.

Tripticen

1) Steroid M e ^ CHy-'C H , _ T i l _ _ . M e

2 ^ Me

' I J hco phi cnh (ngoi tr mch khngi(, vng) ^ .

Cholesterol: Tt c cc im ni ca vng u trans.

H

b) q

- phi cnh

%

' 1 '

phi cnh

c) Me v Me

phi cnh

d) M e^ / Me

.

New man

. Me

phi cnh

Newman

New man

16



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e) Clv^ Cl

/ ^ 7

phi cnhf)

o

ph cn h

g) M e ^ M e .

"

p cnh

*) o v. ,A "H 3 NX >_____

' HB f ~ El Br r ~ 1

(1) v (2), (3) v (4) E nhng tk d cu hnh quang hoc (s nghch ochiu quay trn'hai nguyn t c. Chiu quay c chon mt cch ty tin tnhm th nh nht n nhm th ln nht). (1) v (3); (1) v (4); (2) v (3); (2)v (4) l nhng ng phn khng i quang (s nghch o chiu quay ch trnmt nguyn t c = s nghch o cu hnh trn cacbon ).

3.9

nhau:Ch r bn cht v nhng mi quan h tn ti gia nhng biu din khc

Me Me

(1 ) C6 5Y j h r H (2) h o J h 'O i H

H C6H5

H

c 6h 5(5)

HO H C3

(1): cht erytro i quang .

(2): cht treo l quang

(3): ch t d eu hiih quuiig be

(4): cht confome ca (1) (ch t cju hnh ring, ca (1))

(5): cht coBome ca (2) (cht ,cu hnh ring ca (2))

1 (1}> (4) v (3) 'l nhng ng phn khng i qua ng c (2) v (5) (vgc li).

25



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sau:

cht.

3.10a) Ch r s v bn cht cc ns phn lp th tng ng vi cng thc

6CH, - 5CH = 4CH - 'CHCL - 2CHC - Jc - OH.

-l

Biu din theo Newman hai trong s cc ng phn ca n v ch r bn

b) Cu dng no ng nht i vi mi ng phn lp th ny.

a) Ta c hi loi ng phn: *

- ng phn cis-trans ca hp cht c lia k t i.- ng phn quang hc do hai nguyn t caebon bt xng gn nhau

(erythro, thro).

Tt c c 8ng phn:

- cis erythr d, cis erythro /;

- cis threo , cis threo /;

Th d:

- trans erythro d, trans erythro /

- trans threo d, trans threo /

Hcis erythr 1

Hcis erythro d

b) cho thun li khi biu din c c ng phn lp th, ta th hin,

thng lin kt i trong mt phng. Bng cch cho lin kt i ny vach mt

'mt phng guay c trc l lin kt CC 4 v cu dng bn nha't s l cu dng lin kt C4C5 nm sau m t phng biu din (s gii ta h tng lin kl i

i vi h thng CiCC).

c lY r H v CHv

HOOG > H *

cu dng ny cn c u i nht, vi cc dn xt tyans nhmmetyl cui thot khi nh hng p the CA nhng nhom th Cv

26



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3.11

C bao nhiu ng phn lp th v s nu nhin ca nhni conometng ng vi hp cht heptadien-1,4. Biu dn chng v cho bit hp cht nol bn nht v hp ch^t no l t bn nht.

djb fffibb03 oo (?J

C 4ng phn lp th c ni i:

; , c . " > < " .3 0 = c ^ c 2h 5 3 ^ c = cH h " h cis - cis cis - trans

H ,< x X.H H3C -n / , 2 5 V' = cH W ' "'H 'H ' ^ C 2Hs

trans - cis trans - trans

Mi cu hnh c biu din di dng cu dng s-trans. N tn ti bngs" cu dng s~cis.

H5C2^ .H / v ' - Cu dng ny t bn nht (cng knh

H G ^ 0 rr gia ec gc v lm gim khng gian

3 / C = C w ca h thng lin hp)., H ** .

Bn nht hn l cu dng i xng nhl: trns-trans v s-trans.

. 3 1 2

a) Cc ce\on a - ni i v p-nhm th thuc loi:

R - CH = CH - CO - CH3, nhn c trong phn ln cc tng hp ha hcu c cu hnh trans. c u dng ca chng l g?

b) Ngc l i, bng cch kh xp tc; trn kim loi hp cht ankyn tngng, ngi ta th,c hp cht cn cis. Lc by gi, c phi Gu dng caceton cis-ni i cng ging nh cu cing ca ceton traos-n i i?

c) Ccceton pp-h ai o.hm th thuc loi R - l}c CH


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d) Nu ta ch n loi hai nhm th nhng vi nhm metyl v tr a vbit rng ph hng ngoi IR ch mt c u dng s- transv tnh hnh hc chnh xc

ca nhng hp cht ny l g?

e) Xc nh ha hc lp th ca ceton c 3 nhm th:______________R - c = C - CO - CH,_________________________

H3C c h 3

a) V m t l thuy t ngi ta c th nhn c hai cu dng sau catrans-ankylien-aceton:

(trns s - trans) .' o v Tri' ~ CH3 (trans s - cis)H3C h I

Do s thiu vng ca tat c cc hiu ng khng lp th nn cu dng s-trans l cu dng bn nht. Nhng ceton lin hp ny s

trans s-trans.

b) Tro ng s nhng cu dng c th c ca cis -a nkyiiden-aceton, mt trongs' (s-trans) gp tr ngi lp th bi hiu ng thuc loi oxit de m cs ityl

^ c =(cs s trans) = ^ CH 3 (cj5 s _ cjs)

Nh vy, cu dng c th c ca nhng c ton ny l cis s-cis, s thay icu dng chung quanh lin kt i xy jra cng lc vi s thay i cu dngchung quanh lin kt n ni cc h thng khng no.

c) Cp- rnetyl-ank yliden-ac eton c th tin, biu din 4 cu dng:



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Cu dng ci.s s-trans b cn tr bi hiu ng thuc loi oxit do mcsiiyl.S thiu hiu ng lp h i vi ba cu dng khc, l dng s-trans c ui. Nh vy cu dng c th c trails s-trans.

d.) Trong mt lot cc o^metyl-ankyliden-aceton, 4 cu dng c th c

Ph hng ngoi cho php kt lun hai cu dng s-cs, mt trons nhngs-trans l khng u i lp th. N vn l cu dng c th c trans s-trans.

e) Trong s*4 cu dng c th c v mt l thuyt:

Hai ch t b, loi tr lp th, v trong s hai s-cis, cht bn nh t l c ht ccu hnh bn nht, l cu hnh trans. Nh vy, cc ceton a-ni i b thay thhon ton c cu dng trans s cis.____________- ...r :

3.13 . . . .

a) Sp xp theo th t tnh bn tng n cc ng phn lp th sau: cisbuten2 (1 ) transbuten2 . (2)

- trim etyl- etien (3) - tetram etyl-e tilen (4)

- cis-pen ten-2 (5) - trans-penten-2 (6)

- sym -ditertiobu tyl-etien-cis (7)

29



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- sym-iler t iobutyl -el i ik n- trans (8)

Bit rng cc sn phm (3) v (8) c tnh bn c th so snh c.

b) Sn phm no bn nh irong cc sn phm sau:

- cis hay trans -phenyl2penten2

- cis hay trans-diphenyl-M cyclohexan

- cis hay trans-dibrom o- ,3 -ydohexan.

dfc -db d*bw w OT

a) Cc ng phn trans bn hn ng phn cis v cng hn th v cnhm th ln nht. Tuy nhin trahs penten-2' c tnh bn gn ging vi tnh bn

ca trans butcn -2 .

Thc t cc gc metyl v etyl u c tnh n nh xp x nhau. Nh vy:

Dilertio-butyl-ctilen-cis, i xng, chnh n l khng bn gy nn do scng knh lp th ca nhm tertiobutl.

Nhng nhm th ankyl khng qng knh, lm bn ha cc anken v hn

th na chng khng v tr ttars. '

(1) ~ (5) < (2) ~ (6)

Ngc li, hp cht itertiobuty l - eti le n - trans ixng c tnh bn cao ('cung th t tnh bn ca trime tl

' - etilen) nhng thp hn tnh bn ca tetram etyl etilen

(4) > (3) ~ (8) > (1)

Tm li th t tnh bn ?;ng nhi sau: ' y

(7) < (5) ~ (1) < (6) ~ (2) < (8) ~ (3) < (4).



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28/394


29/394

y ni ta lu trng hp ca nguyn t c khng bt i xng ct chung quanh bi hai nguyn l c cng lnh khng i xng (xem s khngi xng gi 3.20), nhng nguyn t c bao gm gia hai ngu yc n t c khng ixng ging nhau khng mang hai nhm th ha tr khc nhau nhng ch c 1

nhm th ha tr II. Ngi ta bit ngay ch c mt dng meso.b) Khi ngu yn t ' c mang gc metyl v gc etyl

- ng phn p th c meso, by gi c th phn chia thnh hai th i

hnh (meso //, meso d)t rn c 1:.

H5C2N H3C ^ - ' ' ~ *CH ' fr- 2r

H , c ' V / H5C ,^c; - Z.CH

.. trt th iquang threo / v threo /c. th phn i: .

(threo /- threo lh + threo d)

(threo / threo /7/ + threo dd))

h 5c 2>

H3e-)c - 2j c h

V

H}C\ / ........''c - 2ch +

Hsc2' v 0/ h 3C''c - 2ch HsCo 'c - 2c h

c) Vi mi na phn lp th trn, s phn i xy ra o s xut hin catm quana hc h o t tnh trn ,2C. S phn i ny s xy ra o v tr tng i

ca H v OH i vi phn cn li ca phn t.

,OH

V + y * - "S- ...C c......cpIIcu

H

c...

JH

. .c G

Nh vy:

meso hdi

meso //

^ meso h

threo iidi7threo

^ th reo 11h

hre- ^

threo c//;

^ t h r e o li.

7!meso //

threoId/:

/7threo dI

~ ^

meso did3

mtso dih

.threo Md

threo /y/?

thr fc///r

threo W//

32



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30/394

3.15

Nhng cht sau y c tn ti di nhiu dng ng phn lp th khng?V mi cu dng bn nht theo mu Newman

a) 0 - C - OH

o_______

b) H O - C - O - f f

o o

c)

- OH .- c - OH

0 )_____

OH (2)

-(3)

a) (1) khng th hin cc ng phn lp th. Gc - COO H c kch thcln u tin chim v tr xch o.

COOH

b) (2) th hin h ai ng phn lp th

HOOC

COOH

. cs trans *

ng phn trans hai ln xch o bn nht.

Khng c ch t no c ho t tnh quang hc bi v phn t c m t m t phng

xng. ;



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31/394

c) (3) th hin ba g phn lp th:

- Hai ng phn trans vng hay threo

Mt ng phn cis vng hay meso khng hot tnh.I

COOH ! HOOC

COOH HOOC

threo (trans)

OOHCOOH

mes (eis)

Mc d cng tlic ny khng G mt phng i xng, ng phn hot tnhquang hc ny khng th phn i bi v s Gn bng cu dn g a-e e-a rt *

nhanh chuyn ha ng ay thnh d ng i xng ca n.

Tt c cc dn xut hai ln th a-e hay -a ca cyclohexan mc d hot

tnh (rigoi tr 1-4) cng khng th phn i.

. . 3 M

So snh ha he lp th tsa cycobutandiol l',2 v 1,3- Suy ra nguyn tcchung lin quan n a hc lp th ca cp vn g hai ln th.

a) Cyc lobutandiol 1,2 th hin ba ng phn lp th:

- ng phn cis l m eso khng hot tnh* " . --- -' ' * '- ng ph n trails c th phn i thiih hai th i quang threo.

__ __ H ,H . H - H It Y J

z i p ' " _ t 7x OH H O * ^

raeso khng h ot tnh threo

34



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32/394

xng.b) C hai d ng ci s vA trans u khng hoat t nh v chng c mt phn

H O ''nHC

H

cis trails

Qui tc tng qut: Nhng cp vng c nhm th theo ng knh khng cnguyn t c bt i xng; nhng dn xut cis v trans u khng hot tnh.

a) Hp cht ( 1 ) th hin ng phn cis-trans vng hay erythro-threo. ivi hp cht cis, ngi ta c th xc nh mt phng i xng ca phn t. Cc Vnguyn t c 1, 2, 3, 5 ng din.

Nh vy hp cht ny l meso khng hot tnh.

Hp cht trails l threo v e th phn i thnh hai dng hot tih c ribi v n khng i xng na.

b) Trong dn xut (2) lin kt i to s lch i xng v mt phngvung gc VI l in kt C| - 2 khrg phi l mt phng ca s i xng. Nicch khc cc ngu yn t caebon bt i xng 1 v 2khng ging nhau na v c

bn ng phn b i v cis v trans c th phn i thnh c c th i quang ca

chng. -

b) So snh vi trng hp ca cc dim ety l-cyclopenten sa:

/T -CH3

> c h 3(2)

35



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33/394


34/394

b) - Hai nhm m ety l cp i: mt nguyn t c bt i xng.

CH2OH

c th phn il3^ ' 'C H 3

Hai nguyn t c bt xng:CH2OH

*H / ' X /CU Q th phn i

H3C /

1 I xthnh i__xng ea n

/ (erythro)

thnh i

xng ca n

H , c /

c th phn i

(threo)

I thnh i

xng ca n*3^' 'CHj

- Ba nhm m etyl trn ba nguyn t c khc nhau: :khng h ot tnh/CH2OH

h 3c ' 'C H 3

Hai nguyn t c bt xng:H3C

hay I (me so - 1 )

H3C ch 2ohnCH3

HaC

HaC

CH2OH

h a y - - khng hot tnh

(meso - 2)

c th phn i

(threo)

37



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35/394

Ba nhm th cng pha VI mt phng ca vng.

Me f Prc th phn i

- M e , H cng pha.

iPr

. '

c th phn i

Me OH

Me v iPr gMg pl.

H G th phn i

Me Pr

iPr v OH cng pha.

OH iPrc th phn i

"Me

C,tt c 8ng phi = (2

3.20

Cho bit s v tnh cht ca cc ng phn lp th ca cc hp cht sau:

CHOH - ?CHO H - 'CHOH - 4CHOH - 5CH2OH

& & cB? COW) 0

Cc nguy n t 2C X 4C u bt i xng nhng tnh bt i x^ng cachng ging nhau. Nu ta khng k n nguyn t cho mt cp threo v mt

mesoilshiigliot tih. Tlic ra, ngu yn t .khng hot tnh l m t nguyn t cgi b t i xng. N phn i ng phn lp th meso bi v n m,aag hai nhm

38



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36/394

th khc nhau c th chim hai v tr i vi phn cn i ca phn t (xem3.15).

m e s o 1H O H 2C | C H 2OH

>HhIhmesG 2 h o h 2c I- c h 2o h

OH OH

Ngc l i nu ngi ta thay i v tr ca hai nhm th c a nguyn t c

gi bt i xng vi mc ch phn i threo, ngi ta ch i t threo / n threod

threo (/hay d) HOH2C I CH2OH

0 1)H

)H

threo (/hay I) HOH2C 1 -| I CH2OHOHOH

Nh vy ngi ta nhu c: 2 m eso khg hot tnh v 2 th re o hot tnh.

' v ' T ; : "' : J :':' - ' ;!vNgi tL thc hin s kho st ha hc lp th c sn phm sau:

CH3 - COCH - COOH3

h 2I. .

. A = N ., H , c r c 2H5

S iu ch sn phm ny cho cht c tnh trit quantg. Ngi t thc hin

s phn gii cht trit quang nh cht brucine (mt cht ncalid c qu mlin).

a) Cho bi t ngun tc ca s phn gii cht trit quang.

b) Nu ngi ta b ri mt thi gian no mi Qht tron g hai .cht i

nh, chng cho tr li ring l mt hn hp cht trit qung mi. Gii thh kt

qu ny.



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37/394

c) Trong s phn gii cht trit quang n, ngi ta thu c mt trong snhng cht ng phn khng i quang vi s lng ln hn cc cht khc. Giithch.

d) Bng cch cho cht trit quang ban u phn ng vi hydroxylamin, trong mi trng axit ngi ta thu c bn ng phn lp th. Cho bit tnh chtca bn ng phn lp th ny?

a) Axit c tnh trit quan g c th phn ng vi brucine, cc cht ho t tnhquang hc c tnh baz. Sn phm phn gii thnh hai th i quang'c th vitdi dng R - CH - COOH v brucine di dng Rj - N - R2:

' ' R,

A B AB

H @

: . , 1 _ R 4 ^ CO OH

R" R mui ng phn khng i quang

cht trit quang +- : IsT^ R2 ; (+_>| c5 A ( - + )

A (+) > A (h )

S phn gii ny c th o ngu n t H ce-ceton c th en l ha.

CH^ -C- GH COOH =52- CH3 - C(OH) = c - COOH . > r ' . I V. ,



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38/394

Mi phn t enol ha t trit quang ha bi v khi enol to li dng ceton,hp cht cui cng ny c nhiu c may phc hi li di dng (+) hn dng (-).

Khi ln lt tt c nhng phn t c enol ha, hn hp ch ton l nhngcht trit quai,..,.

c) S ph n g ii c tnh trit quang dn n 50% dang f+~) v 50% dng ().Chng ta ngh rng mui AB (+ -) kTtinh v t tan hn mui AB (---- ). Nhng

ngay c khi mu AB ( ) c tch ra khi hn hp, AB (+ -) ty l ging htc th cho tr li mt lng mi mui AB (- -) bng phng php enol hatng t vi phng php ni phn trn. Mt t l phn trm xc nh sn

phm AB (+ - ) s c epim e -ha th nh sn ph m ( - ) v nh vy cht cuicng ny chim t l u i.

Ghi ch: 1) Epime ls loi ng phn trong c s khc nhu v v tr

tig i ca nhm H hay OH trri nguyn t c khng xng cui cng ca

dy. 2) S.epime ha l qu trnh trong c mt.tm bt i xng c thayi thng qua mt phn ng ha hc. ;

d) Nhm chc cetn c th cho hai ng phn oxim tng ng synv. ar.

CH 3 - C - CH - COOH CH3 - c - CH - COOH H I If 1

H O ^ f v + - \ .+N - H ^ OH N+- H

V C / ^ C H , .

Ngoi, ra c tfr thc hi n trng mi trng v mi i ele ctron tin

nguyn t nt gn mt H+, ngi ta thu mui arriohium c th phn ithnh th i quang,

Cui cng ta c: syn +, syi nti + v anti

Ghi ch: Nhng amin t do, mc c cu hnh t din (cp electron t dotng ng vi mt lin kt) khng c hot tnh bi hai dng ca amin t

chyn ha ln nhau nhanh chng v s en bng nhanh chng ny khng chop hp c lp cc th i quang. .

^ ' N : : N ^

Nh ng cht sa u c th hin; ec ng phn lp th kh ng? Ch r tnh chtc th c.

41



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39/394

I

(a)0-0 o yD (2)

tBuOH

'(b)

CH3----- (3)/

Cl

(c) Cl H

H(4) CH3 - CH = c ==CH - C2H5 (5)

CH3

rib


40/394

H,

Cleft*&>TOTOTO

a) 'CH3 - 2C H C 1 -3C H - C 2H5

g h 3

C3 cho tt c kh nng quay bi v c2l c tnh trit quang.

C: hn hp 1-2v d2 -2= quay tri trn c 2, vv...).C; ch /3 .

Nh vy ngi ta c hn hp: r ^ 2 , /-3 quay tr: ngi ta khng th ktl u n . . . d - % / - 3

b) 2 ln siniter, nh S-2, S-3 (cng ch iu ca cu hnh trn hai nguyn tG). Ngt Qth nhn ra ng phn ny l threo. I > OH > NH 2> H > Li

Gc L i-C -H s ln hn 1Q95, trong kh cc gc khc s km hn v gim

theo th t;. ;

n h ^ c ^ h > o h ^ c ^ h l - c ^ h > Ch-C-l i

Ngc l i/cc gc H -C -H tng ng tng theo th t lin quan.- Ly sn phm (1) nh tham kho.

- c u ' L / H2 CKX H CU'^ / H

' W X / iH3C ^ V \ H \ h H2 h

Cl) J ' 02) - ftC C l , (3) f

52



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50/394

Gc CF} th hin obitan ha tr c nhiu tnh cht ,S'(' 3 m in ea flo.FIF C spIF

Trong trng hp sn phm (2): ___________________

Gc 2 s tng ln, gc 4(CF3- C - H = C F3- C - H 2) s tng bng nha. Ngcli gc 1 s h x ung n h gc 3. Tt c cng s xy ra nh th nu gc CF} c m in m nh ng vai tr ca nguyn t dng in gy ra do tnh cht smnh m ca lin kt t do ca n. Trong (3) ngc li, C1 kh xa rih hng

; n tnh cht ca o bitan lin kt ca nguyn t c ang xem xl.

L 4.7 ~ . : . ~ ~ ~ a) Bit rng m om ent lng cc ca lin kt C -C l bng 2,2 D v ca C -H

I bng 0,4 D, tnh m om ent lng ce ca clorua metylen.b) Gi tr th t ca moment lng cc ca sn phm ny l 1,6 D. Da vo

tnh hnh hc ca phn t, hy gii thch s sai bit gia gi t thc v gi tr lthuyt ca mom ent lng cc nu trn. *

Se.H ' ^ c .u \

\ /C1

M-CH,C12= 2. 2 ,2C O S = 2. 0 ,4COS- = 2 , ID

b) Thc t , php tnh c thc hin t mu t din ca c (gc 1095),khng k n s bin dng c t din d m in ca halogen. Hai nguynt halogen c 'm' in cao y nha bi tng tc culomb trong khn g gianv gc C1-C-C tng, lrn gim Ejic - G i s hng qun trng trng php tnh

m om ent tng v n h vy lm gim m oment lng cc.

~ ~ ~ 4.8 ~~ T ~ TT 7 >a) M om ent lng cc ca dicloroetan bng 1,10 D nh it thng. Khi

tng nhit ln n 270, gi moment ny tng n 1,54 D. Gii theh kt

53



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51/394

b) Bin lun cu dng ca sn phm ny t gi tr ca i nhit thng.

a) Nhng cu dng khc nhau c th c ca C1CH2-C H 2C1 nh sau:

C1

m

(1) th m , (3) chekit (4)R rng s phn chia thng k cc Gu dng ca cc hp cht ny nhit

thng thch hp vi dng ( 1 ), cc tng tc lp th v tnh in gia hainguyn t C1 l t nht.

cu dng ( 1 ) c s cn bng v i xng th hin moment lng ccbng 0. Ngc l i, kh i nhi t tng, mt s" phn t no di dng (3), thiumoment hrng cc chuyn sang dng (2) v trong gi tr nh hn (3) v (4) mtt, tt c cc dng c moment lng cc. Vy s tng nhit lm tng moment

lng cc.b) Tuy nhin, n khng tri t tiu nhi t bnh thng, chng t r n

cu dng u i, nhng n khng phi l cu dng duy nht. Tip theo, (2) lcu dng kh hu v lin kt C -C l c mom ent c bn b ng 2,2D, nh vy ngi

ta c th ni, v |-1C1CH ,cw C1 - 1, i D nn cu dng (1) thc t ch im 75%.

4.9

s p xp .cc axit sau theo chu tng tnh axit:

(1) CH3COO H * (2) M ^(Of)O OH (3) CH 2CICOOH

(4) CH2BrCO OH (5) tBu-COOH (6) C H3CH2COH

(7) Cl^CiC OO H (8) H-COO

p ng hiu ng cm VI (rt in t) v +1 (y in t) t c kt qu:

(7) > (3) > (4) > (2) > (8) > (1) > (6) > (5)



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52/394

4.10a) So snh tnh axit ca cc hp cht sau:

C l - CH 2CH=CH-CH=CH-CH2OH

c i - c h 2c h CH2CH2CH2CH2OH

( 1 )

(2)

C 1-C H 2CH2U H

b) B i t rng s phn cc ca lin kt SH l 4,65, OH l 1,88. So snh tnhaxit ca thiolancol sau:

CI -CH 2-C H 2-S H (4) v vi (3).

c) So snh tnh axit ca c sn phm:

N - C H 2- CH2- COOH (5) o 2n - CH 2- CH2- c m m (7)

r i5^2 : H \ ' '

> N - CH2 - CH2 - COOH (6), trong mi trng axit hay bazH

a) Hu ng cm ng gim dn khi mch c no di hn.

- Trong hp cht (3), hiu ng cm ng tc ng ln nguyn t c mang

nhm OH. Ne lii trong hp qht (2), (ocloro hexanol1) c s tt ton b hiu

ng v tnh axit yu hn tnh axit ca (3) l c th s snh vi n hexano-1.

Trong hp ch t (1), ngay c s tp, trung ca c , nh hng ca nhm covn cn, Tuy nhin s truyn ca in tr bi i xng thc hin theo mch cahn k t i lin hp.

S suy yu ca hiu ng t mc duy li h t c a cc m etylen khng bo

gm trong h thng lin hp. Tnh axit ca (1) v (3). tg ng nhau. S

truyn c a hiu ng cm ng khng si vu theo chiu di: a rach, nh ccin t n,mang nhm vinyl. ( 1 ) v (3 ) l nhng nci 1 vinl:

Tnh axit: (1) ~ (3) > (2).

b) S truyi ca hiu ng cm ng ty*thuc ki ng ch vo s; pc r^e

(relais) ( hay 7t) m cn vo b n ch t ca cc relais, c bi t l s ph n cc calin kt. Do lin kt SH c th piin cc hri QH v m* hig c, Ttlgen s

rt quan trng trong thiol hn trong ancol tng ng nr :



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53/394

*

c) - Trong mi trng baz, mch s lan truyn ca hiu n cmng khng Lhay i v N 0 2 c nh hng quan trng hn NH2 v NH2 quantrng hn NR2.

Tnh axit (7) > (6) > (5). -

- Trong mi trng axit, cc i in t 5- sn c ca N trong (5) v (6)lin kt V I H+, v cc nhm mang N c in tch + s tr thnh nhng nhm htin t mnh hn.

Tnh axit (5) ~ (6) > (7).

?*

4 . 1 1

Cho bit nhng dng gii hn ca cc hp ch t sau:

1) CH3-GH=CH-CH=CH2 2) CH2=CH-CHO 3) Ci-CH=CH -(ZO-CH,

4) / = \Clc / C0 -C H 3

\__/5) C1{ ^ CO - c h 3

\__/

6) C l \ ^ C O - C H 3

0

rfla.t&%or cEFwF*. ; ' . ; - , v . . v ' ; ; : /*. ; , /

1) CH3 - CH - CH = GH - CH2 CH3 - O T ^ f ^ C H = * C H 2 CH3 -+CH - CH = CH -~CH2

(A ,) , (A) . (A 2)

(A)), (A) v (A2) l nhng dng gii hn. Nhng A| t bn bng A 2 donhm CH3y i n t (+1).

2) C I l j -C t H ^ C - H CH2 - C H - C , H

' . h :

y, s bt nh x thc hin theo mt chiu duy nht, do m inmnh ca nguyn t oxi. !

3> : ^ CH = 'CH^C - CH3 i'cI = CH - CH = c - CH3IU I _

> : P*:

Cl l cht m esom e cho.

56



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54/394

4) : c - CH^ : Cl = f ~ V - +c - CH3

> ' w : : -

S bt nh x khng xy ra do khng c s lin hp.

5) : C l - f ^ c - CH, : C1 { ~ ) r = c - CH-,

^ & \ ' w : l r '

Nguyn t clo khn g thuc h thng lin hp.

6) CH, c h , ^

: C l \ C ="o" -** :C , .c0 : \JT / \ y /

7 V 'v > " ; V y clo tham gia vo s lin hp'.

4.12

Cho bit nhng dng gii hn ca cc hp cht sau:

1} < Q - CHO 2) H O ~ Q > 5) H3C - oQ COCH3

57



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55/394

4.13

a) Nhng hng s baz ua amin sau th hin tnh tng quan hp lkhng'? .

(1) CH3NH2 Kb = 4,38. 1(T4 (2) (CH3)2NH Kh = 5,2.Q-4

(3) (CH3)3N K, =5 5,27. cr5

Ngi ta c tfr ra quy tc tg qut da trn tnh baz tng i c acc amin ( 1 ), (2), (3 ) c khng? (bng cch m rng ra i vi amii I, I v

III).

b) Chng minh bng cch da vo cht mesom e, tnh bazc ca anilin i

vi cc amitt bo cho t?c, bit rang; Kbamitn = 3,83. 10l()

c) So snh tnh,baz ca mQta. v gara-n itroanilin 4q vi ailm.



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56/394

a) S in ly thc hin nh sau:

CH3NH2 + h 2o -* CH3+NH3 + HO"

___I V _ [HQ-][CH'+NH,3____________[CH3NH2]

Nh vy, ie ty lamin c tnh baz hi mnh hn monoety l amin v gp 10ln tnh baz ca trietylamin. Khng e quy tc tng qut p dng cho tnh bazdca rain. Tuy nhi n c hai y.u t' i. khng (facteu r antag onis te) c nh hngn tnh baz.

- M t y u t in t lin k t vi kh' nng' cm ng cho ca nhng nhmmetyl c khuyqt h^ng gia tng m t in t trn ng uyn t nit v nti vylm gia tng tnh baz t amin I n am ii l !. .

- M t yu t lp th lin k t vi s cng knh ca cc nhm th gn vinguyn t nit v lm cho kh nng tip xc ca i in t sn c tr nn khkhn (lm giin tnh baz). S cng knh ny tn ti nht l vi amin III v nhhng ca n ln hn kh nng cho ca nhm th (t lm gim mnh Kb ca

trietylamin).

b) Hng s' Kb ca an lin chon 106ln nh hn hng s Kb ca amin

bc I v II. i u n do s to cht trung gian. (l,a msom rie, s to Qhtmesome) ca nhn thm benzen lm gim tnh i nhn ca nguyn t mt, hays bt nh x ca cc electro n l m b'n amin. chnh n, gy thi t hai ionanilinium c to thnh trong s in ly mi trng baz.

c) Hp cht, meta-niteoaftilifi, (Kh a 4. t J2> c tnh, baz y so vi do kh n ng h t in* t -I ca nhm nitro lm g im m t in t trh nguyn

I II II . II

Q * " " 0 - * * ' Q oNH2 + NH2 + NH2 . + NH2

Ion (A) khng bn v nh vy khp c to thnh (t Kh gim)

NH3



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57/394

# ,

*

t ni t ca nhm amino NH2. Mt khc, h thng cng hng vn khng thay

i trn nhn thm.

Hp cht paran itroanilin (K b = 1. 1 0 'l3) c tnh baz cn yu hn bi vngoi hiu ng ht in t ca nhm nitro nh ni trn, cn c s bt nhx ph ca nhm nitro:

dng gi i hn ph

4.14

a) Chng t tnh axit ca axetylaxeton, etyl axetylaxetat v malonat

dietyLb) Hng s axt cua axety laxeton nhi t thng, v trong rie l

Ka = 1,5. 1~9, ca etyl xetylaxett l Ka - 7 , 1 - 10~", v cui cng Ka camalonat ietyl khng th xc nh .trong nc l 1CT15. Chng minh nhng skhc bit ny.

Y c) Ch bit nguyn tc ca phn ng ncoyl ha (1alcoylation) c th toba sn phm y v cho rng nu s to thnh ea dn xut c xt, cht trunggian cn thit, c th to t lung dch xt.


58/394

(1) c h 3 - c - c h 2 - c - c h 3 - h * \ c h 3 - c - CH - c - c :h 3 ([)

& & CH , - c = CH - c - CH , (I')

3 I 3o - o

(2) CH3- c - CH2- c - OC0H5 . H +

& 6

CH 3 - C - C H = C - C H 3 (I")

If A___ o ---- -------O '---------------

CH3 -C -CH - C- O C 2H5 (II)

O ' o

c h 3- c = CH - c - o c 2h 5 ( i r ) ch 3- c - c h = (p -o c 2h 5 (II")

O ' o , 0 o -

c h 3 - c = c h - c - OC2H5 (W) 3 I If 2 5

o - o

!0 ) G2H5O | CH2 c OC2H5 Ho o

c 2h 5o - c - c h - c - o c 2H5 (III),o o

c 2h 5o - = CH - c - o c 2H5( i i r ) ^ ^ c 2h 5o - c - cH = 'Xj:-0 C 2H 5 (IH")O ' o o O '

: ; , K^ K ^ c ( x !i S o o M i l -5 H r' ; ? ; I

xety lxe tat etyl - Ku =

M alonat etyl - K i

[II] [H+][CH,COCH2COOC2H5]

= 7,1. 1.0'

[C2H5OCOCH2COOC2H5]= 10'

Cc baz in hp I, II, III c lm hn bi s msome, nhng s bnvng khc nhau trong tng trng hp. Th t kh nng n hn in t nh sau:

c h 3 > - c ^ - c 2h 5


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Tnh bn (le poids) ca cng thc II, II \ I hung chi cc cng thc III'v III (mang hai gc th C O -O C 2H5 lm gim s ht in t), thp hn tnhbn ca cc cng thc I v I . Th t tnh bn s l I > II > III, v th t tnhaxit tng ng cng nh trn.

c) Trong cc phn ng ancoyl ha, ngi ta dng cho c li tnh axit yny bao gm gia hai nhm -C O:

4 R - C O - C H 2-C.O-R (R=ancoyl hay ancoxy) R- CO - CH ( N a) -CO - R + RX

- R -CO -CH (R ) -CO -R + NaX

Theo thuyt s xt ha, m u cho s ancoyl ha, c th thc hintrong mi trng c nc (bi xt) hay Irotg mi trng hu c (bi s ancolath ca xt). T xt, ngi ta c phng trnh phn ng sau:

R - C O C H 2- C O - R + NaOH ^ R - C O - C H ( N a ) -C O - R + H 20

c th th chin c tin trith trn (tc gii un s i/ phn tch ccdn xut c xut ha bi nc), th axt ca cc hp cht ving ancoyha phi 11 hn tnh axit ca nc. l trng hp i vi axetylaxeton vaxetylaxetat etyl, v khng phi l i vi malonat etvl v hp cht ny bt bucphi c xt ha bng cch ancolat ha v khng thc hin trong mi trngbaz c nc (xem hng saxit). S phn ng nh sau:

EtOH + Na EtONa + 0,5H2

C2H50 - C 0 CH2C -0 C2H5 + EtONa -> C2H50 - C 0 - C H ( N a ) - C 0 - 0 C 2H5 +

EtOHC2H5OCO-CH(Na) -COOC2H5+ RX C2H50 - C 0 - t : H ( R ) - C 0 - 0 C 2H5+ NaX

Ngi t .cng c th thc hin qu trnh phn ng nh trn vi P-dixctonv este 3-xeton v hng saxit ca nhng hp ch t ny hi khc vi hng s axitca nc.

4.15

Sodn.

snh tnh axt c-a cc hpcht sau. sp. x p chng th eo th& t tng

1) Q - o -h 3) Q - o - H 4)

2)o - - H

5) C H , C O - o - - H

62



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60/394

1 ) 0 -O-H ^ Q - o - + HH

2) V o - H H+ + o o

Baz lin hp c bn vng nn axit ny rt mnh.

3 ) "=5=^- II* + 0 - O - -

B az lin hp khng b n, nh vy hp cht ny c tnh axit nh (1).

/>/

By gi s b t nh x ton vng khin cho axit ny tr nn mnh hn (2).

5) /r~ \ ..Me - c - H Me - c - f l - + H+

^ W / . l x==/

y, s m rng h thng lin hp rt quan trng v n lan ra n nhm

axetyl ngo i vng, (5) m nh hn (4)'v th ttnh axit gim nh sau:

(5) > (4) > (2 ) > () > (3)

63



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1 )

a + H oH

Khng c s cng hng' trng dn g proton ha (axil lin hp) vi ccelectron t do ca nguyn t nit, trong kh baz ea n c bn h a bi scng hng (xm tnh thm chng 10). Nh vy baz ny yu bi v s cn

bng chuyn dch t ph i sang tri.

Dng e tnh baz c lm bn hn i vi axit lin hp th baz cngyu. Dng c tnh baz c lm bn bi s cng hng ph (2) v cn hn.th na l (4). Ngc li, trong (3) hai nhm metyl, do s cng knh cachng, bt buc vng mang chng qay chung quanh lin kt n hai vng. Cc

obitan 7Xca vng ih hai lc bay gi khng cn song song vi Gc obitan ncavng th nht v kh ng c s tri rng ca h thng lin hp vi ( 1 ), t ssp xpi: (1) 3=(3) > (2) > (4).

64



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bdjb dfe>CO CO CD

- A ni lin '(l) bn o s cng hng v axit lin hp (ionanilinium) tng ng th khng.

Cn bng trong phn ng: Ar NH,) + H A r- 'N H ,chuyn dch mnh theo chiu 2 v anilin l mt baz rt yu (Khi = 4.1(rl(l) sovi baz bo (Kb = l(r4).

- N,N- imtyl anilin (2) cng bn tng t o s cng hn, nhn-s; mt in t trn nguyn t nt c tng thm do hiu ng cho ca hai nhmmelyl. y, yu t" lp th i khng t tc dng hn trong dy bo v i inl b ht nh x trn tt c vng v li vo vn cn dng. Nh vy (2) l

baz mnh hn ( 1 ) (K h- 1,15.l _y). .. ..

- N,N -dimetyl octo toMin (3) th hin cu trc t cng hng.

S bn ha: H3C ^ C H 3N

1 CH3

h 3c c h

+ NII 'QCH,

b cn tr. mt phn v s cng bc lp th gia hai nhm metyl . Dang c tnh

baz t bn d lin kt vi proton, (3) c tnh bazd mnh hn (2) khong 6 ln

hn(K M= 7,3 .10~V- N,N -dim ety anilin c thm hai nhm metyl o v o. (4) l mt baz rt

mnh do s lin hp gia hai i in t t do ca nguyn t nit v vng thmbi cn tr lp Ih. Hai nhm th metyl ca nguyn t nit t trons mt phimvung gc vi mt phng ca vng: 1

v tnh baz ca (3) s tng t nh tnh baz ca amin bo,

Tm li: (4) > (3) > (2) > (1). .

65



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63/394

, Chng 5 v 6 gi i thi v c c h cc phn ng th i nhn v kh( r e a c ti o n s d e s u b s t it u ti o n s n u c l e o p h i le s Gi d ' el im i n a t io n s ) . N h n g o i c c h

khc, nh ng l (homolse) v d l (htroys) s c kho st tmns ccnhm chc khc nh. c bit:

T S thay th gc c kho s t chng 7 (arkkn). :i

- S cng s c e kho st ch ng 8 (inker).

- S thay th'i in t c kho st chng 10 (aren).

: - S cng i in t c kho st chng 8 (anken).

- S ciii i nhn c kho s t chng v 3 (hp ch c - kim .orgno- mtalliques, v cacbony).

- Phn ng chuyn v in t vng (les reactions pa r transferi

eclronique circuh re) c kho s t chng 8 v l (dien lin hp v c -kim ) ' '

- S sp xp i (rarrangemeiit) c gp trong phn lt cc chng vc n li di dng cu h i ph.



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Sm3llSS'

5.1Kho st ng hc .phn ng ca HC1 vi cc hp ch t sau: bu tanol-1,

ancol tertiobutylic v bcyclo[2 .2 . 1 ]heptanol-l dn n cc kt qu sa:

V = k|[Cr][butanoI-l] ; v2= k2[tBuOH] ;

V.3 = k3[.b icyclo [2.2 .1] heptanoll][C l' 1 vi ks


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66/394

c) Thm nc vo hn hp phn ne lm tng yn tc phn n". Chngminh hin tng ny, bil rng hng s in mi (la constante ilectrique) caH20 rt cao so vi ca axit axetic. ,

d) By gi ngi ta .dng bromua tertioheptyl quay tri ging nh snphm ban u v tin hnh mt Tn na phn ng th vi ax it axe tic nguyncht.

- a ra m t phng php thc nghim n gin cho php theo di tintrin ng hc ca phn ng.

- Khi ngi ta thm axetat natri vo hn hp phn ng, phng php trndng nh ch ra mt s gia tng nhanh chng tc axeto gii ( 1actolyse).Tuy nhin nhng php o ring v ng hc ch rng, ng vi nhng g ta

bi t vi bromua te rtiobutyl , khn g c g thay i; Gii thch s bt bnh thng

thc nghim n.

a) Nhm i nhn CH3CO" va thay th Br - trong bromua tertiobutyl lcht nn (le substrat). Qu trnh l s thay th i nhn.Ngi ta U rng trongcng mt thi gian, dung mi chnh l tc nhn. N thc hin qu trinh dung mi

phn (la so volyse), ch nh xc hn l s axetol phn (1actolyse)

b) Nu ta thm ion axetat vo trong dung dch, ngi ta nhn th rigthc t tc phn ng khng gia tng. Nh vy nng cc ion axetat khngtham gia vo phng trnh vn tc vn ch ty thuc vo nng ca bromuatertiobutl.

V = kl(CHO.,C-Br]

Nh vy ta c phn ng SN)

(CHOCBr (CH^C* ch?co ' H CH^COCOCH,

giai on chm (s ion ha ca bromua v s to thnh cacacbocation tng ng) xc nh tc chung ca phn ng.

Cacbocation c u i: Bi S th ba ln (la trisubstitution) ca cation c lm bn bi hiu

ng +1c nhm m etyl.

^ Bi s gim p lc lp th mang:li crig thc phng:

CH-,



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67/394

c) CHCO OH v HOH, cc dun mi prolic (sovants protique, duim mc lin kt hiro) c nguyn t H linh ng u i c hai s ion ha cua lin kt

Nhng s ion ha thc hin m t ln, s phn ly c u i bi nhngdung mi c hng s in mi ln dung mi ha hon ton cacbocation b clp. Nh vy, phn t nc nhiu cc hn axit axetic lm gia tng s to thnhccboction v lm bn vng n. Tc phn ng th s gp thm (accrue).

d) Brom ua te rtohep tyl quay tri bt buc c cng thc sau:

Ngi ta tip-tc theo di tin trin ng hc ca phn ng bng s khost phn cc v.ngi ta bt u t hp cht c hoi lnh quang ha (xem bi

- C s hin diii ca axit axetic nguyn ch't xy ra phn ng SN| bn

thng vi s trit quang ha (la racmisation) v s nhn axetat khng, hottnh. Thc t, axit axetic t i nhn v s tn cng i nhn trn ccbocatioii

khng xy ra kh hp cht sau cng ny hon ton b c lp Br. Trong iu kinry s tn 'cng xy ra t hai phia c mt p.hng cacbocaton.

C s hin din ca ion axeta t natri CH3COO' nhiu i nhn hn t

cng cacbocation. S^o di i sng ca cacbocation s ngn hn v n b tncng trc khi c lp hon ton vi Br". Nh vy, mt phn ca bromuatertioheptyl chu s nghch o cu hnh mc d c ch SN v axetat

tertioheptyl khng hon ton bt hoat.

\ \ * -CH - X

/H (ca dung mi)

H5C2----- -C - Br i c /

5.5).

H3Cx

+ / C H 3

HO^

= o o = c^O H

(lon b dung mi ha i xng)

C - O - C O - C H ,t * :

(sn phm axtoL phn b trit quang ha)

70



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68/394

\ H ;C - COO

f+

--- c - Br H3C - C OO'

/(ion dung mi ha ht i xng)

/H?c- COO - C

\Ghi ch: Hydrogen-bonding solvents are called protic and those with no proton for

hydrogen-bonding are aprotic (Org. chemistry, Cram, page 388).

a) Bromua butyl bc II v dimety-2,4 bromo-3 pentan ln lt b thyphn bi hn hp nc axit fomic v hn hp nc - axeton. Lc by gi

trong trng hp 1 cc tc thy 'phn rt gn nhau, trong trng hp 2,bromua buty l bc II c tc thy phn 10 ln nhanh hn tc thy phn cadiirietyl-2,4 bromo-3 pentan. Suy ra c ch ca hai qu trnh thy phn.

b) Bromua biityl bc II quay tri chu s thy phn khi c s hin in cahn hp nc - fom iat natri cung cp: :

- M t lng nh ancol tng ng

- M t hp ch t th hai m S phn tch bch phn chng t rng s ngng

tu cacbon khc rihair v ph hng ngoi hin din trong gii 1710 cm-1. Chng

t k t qu ny v ch bit h hc lp th ca nhng sTphm Ih. \c) ciorua mety 11 benzyl qay tri chu cng s thy phn cung cp mt

hn hp hai hp cht khng c hot tnh. a ra mt cch gii thch s bin mtca hot tnh quan? hc.

a) Hai brom ua (1) v (2) u l bc II, c th cho cc phn ng SNi cngtt nh phn ng SIS2. S la chn ce iu kin thy phn s quyt nh loi

phrrng \ -

- Vi hn hp nc - axit fomic, hai hp ch t chu s. thay th i nhn bi

c ch nh nhau m giai on chm khng phn bit r (riest pas sensible ) skhc nhau v cu ,tre cia hai bromua.' ( '

- v


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Trong trng hp 1, hn hp nc - axil fomic u ai s lo thnhcacbocation t s thy phn.

CH - Br (SN.)

Trong trng hp 2, hn hp nc - axe ton , t in ly nhiu, khng u is d ly ny v xy ra cch SN2.

1 )

2)

CH + BrCH - Br

OH

OH '( 2)

hCH - OH

HO - CH + Br

Bnh thng trong trng hp 2 s thay th ca (2) chm hn trong (1) dnhm OH tip cn kh khn vi nguyn t c cng knh ca gc ispropyl.Thc t s thay t h SN2rt nhy cm vi s cng knh.

b) Vi s hi n din ca hn hp nc - axit fomic ngi ta e kh nngth i nhn gp i: s thy phn v fomol phn (a brmoyse) do tc ng cahai tc nhn i nhn l H -O -H v H-C O ~. Anion fomiat l tc nhn i nhnmnh hn phn t trung tnh H20. Ngi ta thu c nht l sn phm ca sfomol phn:

Me

Et-&r

M e

Me

Et /

\s trit: quang ha / Et

+, , H20CH CH - OH

HCOO - "kh nng nsghch' o

(xem 3.2 4>

Me

Et

\ T,CH - o - CHO/

Mt phn ca fom iat ny s quay phi.

c) GfiH- - *CH ~ Br trong cng iu k i n cung cp nhng l l ca SN| hai

"M sn ph m th: ancol v fomiat. Ca tion benzyl, c bnvrg bi s cng hng, c i sng1kh di mc tnh i nhn c HCOO ~vnh vy tao S trict quang ha ton phn.

72



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(2) AcO 1'

[a] = +32 18

c 6h 5c h 2

M e^

8 CH-O-HL i A j H 4

(3)

M e^

CH-O-CO -CH

LC6H5CH2 [a] - -3 1

C ch ca s axeto phn tosylal mety 1-benzyl cachinol l g?

(jb ()COw JXi

Phn ng 1 l phn ng este ha bo tn nguyn t oxi c nh u caanco v ch dng tnh axit ca nguyn t H ca nhm hiroxyl.

Phn ng 2 l phn ng thay th i nhn tht s: '4

R-*OTs + AcO -> R-OA c + OTs (Ts: losyl)

Gia ri 3 cho i hp cht khi u khng n


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Tv thay th c xc nh ( mi mu trch bi RMN t hn hp (t s

cng cc mi ca sn phm ban u v sn phm sau) n gin hn bi snh lng ha hc cc nhm chc. Ngi ta ghi nhn rng ancol v clorua c

cngJdi nng quay c bit.______b) Sau khi thay th 20%, s gi m kh nng quay s nh th no khi HC

phn ng vi metyl tert iobutyl cacb inol quay tri bng c ch cng nhn r ng ch

c c ch hp l nht tc ng?

a) CH3-CHOH-CH 2-C H 3 + c r -> CHs-CH 2-CH(C1)-CH3

1) Gi s c ch phn ng SNi .

100 phn t /lc bt u

20phn t lc thy th v cho 10 r/ + 107

(N| = s trit quang ha m hot tnh dn n khng c g. i vi 20phn t).

By gi ngi ta c 90d + 10/ v phng din hot tnh quang hc tt cxy ra nh ch cn 80 phn t d

Nh vy, kh nng quay biu kin gim 20% sau khi Ihay th 20%.s NI: Tc thay th = Tc trit quang ha.

2) G is c chp h n ng l SN i

100phn t y lc bt u

20phn t c thay th.

Cn 80 phn t /.

20 phn t c thay th tr thnh / (nghch, o cu hnh) v khnghot tnh 20 phn t mi /(khng h ot tnh ca hn hp 20 /+ 20 /). -

Tt c xy ra, v phng din hot tnh quang hc coi nh ch cn 60 phn

t d. Nh vy, kh nng quy hiu kin gim 40% sau khi thay th 20%.

SN2> Tc trit qunng ha= 2. Tc tha ih.

Nh vy ' ch y l SN2. . '

b) tB u-C H O H -M e -2- tB u-C H C l- M e



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72/394

Calion tBu-^CH-Me hn v cc nhn th c nhnh v SN: b han ch donh hng lp th ny nn ngi ta ii s r;m c chphan n < 2 5 ' CH3 - N+ - CH , c r H3C -----N: + H c

H ,c/ h 5c { V zh 5 H.C

CoH2rl5

S gia tng tnh phn cc ca dung mi i km vi s gia tc phn ng, tc gim nng lng hoi tnh.

SN,:. H5C2

H C -C l

H5C2

H


73/394

H^Ct C7H5 r-'ij\ /

c - N + - CH3

H ^ C H 3

Cl

iu ny l bnh thng, v nu ngi ta xem hai s phn ng c th c

iren thy in tch ton phn ca trng thi u nh hirin lch trng thichuvn ticp ((l l trng hp t 11a qui nh o . v nng Idng' ca s solv a t h atrng thi trung gian ny quan trng hn trng thi u.

Nng lng ca s so lvat ha t l vi cng 40 v s tp trung ca intch. Ni cch khc, nu in tch xut hin trng trng thi chuyn ip, phn r s tng tc bi dung m ngy cng phn cc (nh lut HUiGES &INGOLD)* s lm bn bi s dung m i ha phc cht ca s chuyn lip.

S gia tc ny, bnh thng s qun trng i vi SN| hn SN2 bi in

tch lc by gi t b phn tn. y s gia tng ng mi phn cc i t quantrng, ta c kh nng xy ra phn ng SN |. *

b) S thy phn mui am onium bc IV l phn ng SN2.

HO- +H5C2v / u n 3

CH - + NH.C5^2 \

c h 2

- CH.3 HOl CH

CH,..... CH.... N - CH3

H5C2 XC^Hs N c h 3'2ri5

, , .... ' .

HO - CH + (CH3)3N; : 5;'

'Ngc li trng hp trn, in tch ton phn ca trng thi chuyn tipnh hi trng thi u. S gia tng kh nng ion ha dn n, do s bn vngca trng thi u, s gia tng nng lng hot ha tc l lm gim tc phnng.

1 = in tch tng ng trong trng thi

u v trng h chuyn tip.2= in tch thp hn trong trng thi

chuyn tip.AF = nng lng hot ha

: = nng lng dung mi ha

Nh vy ph n ng s nhanh hn trong trng hp dng hn hp nc -axeton 50%. Ngoi ra cn phi xem xt hiu ng dung mi ha c bit.

76



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74/394

5.7a) Gi s cho rn phn ns ca hn hp nc - axelon 50/f vi mclyl-3

cloro-3 penten-1 v vi meiy-3 cloro-3 pentan r cng loi SN|, hy ch r sthy phn no 'nhanh hn.

b) Trong trng hp 1, ngi ta nhn c hng nhau cc sn phm ancelbc . Gii thch ti sao. Hp cht n o c hot tnh quang hc. Ancol no c L lcao hn?

c) T hp cht no khc ngi ta cng thu c hai ancol, t l tdng ick chng c khc nhu khng?

; a) Hai c ch SN bao hm bc chuyn ca cacbocation bc IV bn:

l a ) ^ c , _ h 5c h 2= CH - C - c 2h , c h 2= CH - C - + cr

ICl (1) C2H5.

H p UHO- | / C 2H5

--- -V c h 2- CH - c "(2) 'C 2H5

. g h 3 - c h 2 C- c h 3 - H 2 - c + + c r . ^ C H 3 (3) ^ C H 3

HO, CH3 - C H , - C

(4) ^ C 2H,

Tuy nhn, cacbocation (1) r rng l bi hn cacbocation (3), (1) bn dohiu ns cng hng:



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75/394

b) S thu nhn ancol bc I tng n>i vi s tn cim ca OH " l mi d

Z1 h n k h c, cho sn p hm :

Cation mesome (trung ian) bc I t bn hn cation bc bn. T hai dn"gii hn phi to cacbocation bc IV bn. Ancol thu c vi lni nhiu s lancol bc IV (2).

c) thu c ha ancol nh nhau, phi i t hp cht khng phhalogeiua bc IV, m t halogenua bc I cho li cng cacboction trung

gian: 1

T l hai anco nhn c s ging nhau khi t halogenua bc IV hayhalogenua bc I, V I hai hp cht ny s cho cng ion mesome M. S thay th

SN| a n hn hp sau cng c cng thnh phn. Hai halogenua ban u c

kho st xy ra ssninG

(dn n cng ion trung gian) v c g i h ining ng phn hon v m u i m r c y .

Di t (A) sang (D) v t (B) sang (C) thc hin hi phn ng SN| (s di

chuyn ca ni i).

C2H5HOCH2 - CH = C

\c h 3

c 2h 5 - c = CH - CH 2C 1 C2H5 - c = c - +CH2CH 3 c h 3

h 5c 2\

h 3c+c - c h = c h 2

h 5c 2c = CH - CH2G1

H.iC ^(B)

C i = ^ cl c h 2

(M)

h 3c ^

H

h 3c ^C - gm = g h 2

(C)

78



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76/394

a) Clorua crotyl tham ia phn nti bc 2 (bc 1 i vi mi tc chi) vi

dn xut ca malonai dietyl c nalri ha.

- Lm th no iu c h dn xut cui cng ny, bit rng hng s axit

ca malonat dictyl l 10~1 ?- Sn phm thu c ca phn n


77/394

- Tn cntr i nhn mt cch bnh Lhng Iron nguyn t cacbon mans clov dn n s thay th i nhan loi SN2 c in:

COOEt_ I E tO O C ^ ^-COOEt

EtOOC - CH -

^ ICH2 rr CH - H - CH 2CH3 ------ CH2= CH - CH - CH 2CH3 + C1 -

- Tn cng i nhn trn metylen cui vi s vi s di chuyn ca lin kti rt c th phn cc v S chuy n c tm phn ng (c ch SN 2):

EtoocCH - CH? - CH CH - CH2CH3 ------

E t o c - '

EtOOCv^ - .riCH CH2 - CH ==CH - CH2 - C H | + c rE t O O C ^

S chuyn ca tm phn ng ny s cng d dng v cht i nhn ln hn

v nguyn t cacbon, trung tm ca s thay th bnh thng, cng knh hn, tuynhin iu kin khng phi l mi trng phn ly thch hp SN| v SN |.

5.9a) Pheny-metyl-cacbii)l quay phi, ch ha vi SOCl2, lo clorosulfil (c

th c lp c),- chuyn ha thnh clorua (ca ancol ban u) c cng cu hnhvi ancoi. S bin i ny l n phn t (monomolculire ).

Tnh ng hc, c so snh vi phn ng ca ancol ban ii vi HC1, chophp xc nh rng s gi cu hnh khng do s tham gia ca nhm phenyl trongnhng iu kin th nghim dng. ngh c ch tng hp vi nhns quanst.

b) S bn i ca lorsulfit c thc hin trng pirid in. Tnh ng hcbc 2 cng c quan s t nh s nghch o cu hnh. Gii thch hin tng ny,

so snh vi trng hp.trc. c) Phn ng ca clorua tionyl vi ancol neopentylic trong ens iu kin

dn n clorua tertioamyl v mt lng-rVnh hp cht corua neopentyl,nhng phn ng x ra kh khn hn phn ng trc. Ngoi ra trong ung mi

yu e, ngi ta c s'duy tr cu hnh, irong khi Irong dung mi mnh 8, ngi lac s trit quang ha. Gi thch nhng quan st c. '

80



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78/394

H,

1) C6H5 - *(

b) Nu phn ng c thc hi n c s hin n ca pirdin th s xy ra s

thay th SN2vi s nghch o cu hnh: vV

H5C6^

CH - o - S - C1 x= / _/ H ^ /

H3C 7 O H3C /

o

O h 5c 6 !N: 5 6\ ^____ CH-0

/ ^ 6 ^ 5 / = \V Cl - C - H + + S0 2

Ch t trung gian clorosulfit to vi piriin mui pyrydinium.

c) u tin xy ra phn ng:

H 3C \ SOCl2 H 3C \C - c h 2o h ------- c - c h 2 - c h 3

H r / r / jH3C CH 3 H3C C1

Tt c xy r nh th G s cvuyn y W agner - M eerw ein vi s hin

din ca cacbocation. Phn ng khng thun tuy thuc loi SN|. Ngi ta c thxt n ph n ng SNi vi cp in b t i xng v s bo ton cu hnh.

Y ^ l ^ - ' c l - so 2 Vc C1 - C ; -- c C1/ ^ f I ' s 0 2 '

SI



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79/394

Cp ion khng b phn ly khi hng s in mi khng qu cao, nhng

cacbocation c th chuyn i.

CH1u 3Cv 'C l - I 3

H3c - c - + c h 2; C1 - C - CH, - c h3--------- Hc /--- x' s 2 ----------------------- h3--------------------- ------

S ny gii .thch rng phn ng xy ra kh khn hn trong trng hp

ca phenyl-metyl-cacbinol ion metyl-benzyl bn o s cng hng. Ngc

li, khi E tng cao, c p ion hon ton b in ly, c ch tr thn h SN| thun ty.

V 5.10

I Ngi ta thc hin s solvt h clbro-1 metyl-2 cclopropan erythro bihn hp nc - axe ton 50%. C ch thuc loi SNi (s xc nh ng hc), tuy

nhin ngi ta quan st thy sn phm cui c kh nng quay. Gii thch hin

tng. .

thrco (trans)

S tn cng c thc hin t c hai bn ca cacbocation, nhng khnglm mt kH nng quay v sn phm solvat ha mang hai nguyn t cacbon bt

xng k en v k h nng quay erythro v threo khc nhau. S chuyn t hpcht rytho (cis) ri hp cht threo (trans) c thc hin vi s nghch ch

xy ra trn hai nguyn t cacbon bt i xng. Mt s nghch nh th l s

epim c ha (lcpimcrisauon).

* Nu ta c nhm cng knh hn th mt pha tn cng s kh ng T gi l s cm ng bt i xng inductn asymtriqu).



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80/394


81/394

CfiHs - CH - C H -C 1 h 2o C6H5 - CH - C H - OHI I - 7777*^ I I

CH3 CH3 h0 c h 3 c h 3

- S trit quang ha c th xy ra (SN |) trn c 2 dn n sn phm cn chot tnh do s bt xng ca C3.

- S nghch o cu hnh trn C(SNt) khng th d nn snphmkhng hot tnh v c 2 v c 3bt i xngkhc nhau v khng thto kh nngquay c b it c cng gi tr tuy t .

gii thch ngi ta da vo s tham. gia ca nhm phenyl.

+ Cl tn cng trn C2

C s gi cu hnh c 2v C3v tip theo l s bo ton hot tnh

H ^ \ ^ > CH3tn cng trn C3 > c 3 2 G

H , c ^ v ; ,v ,

S nghch o eu hnh trn c 2 y -Cv

Nhng hp cht thu c t s tn cng trn c 2 v C c ha tinh gingnhu. S tn cng trn c 2v c 3dn n cc ch t i hnh ( nantiom orphe) viiu kin l s tn cng ny cng c kh nng x y ra trn C 2v C, v sn phmc cu l b t i xng.

5.13S axeto gii hp cht

' "1; ' H3C - c - CH -C H 3

c .I t s

xy ra theo nhng ghi nhn thc ngh im sau: ,

- S cng axetat natri thc t khg lm gia tng tc phn ng

84



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82/394

- S cng nc lm gia tng tc phn ng.

a) Cho bit c ch s axeo gii? C ch dn n s to thnh mt hay

nhiu sn phm ?

b) S axeto gii hp cht

____II5C2 CH - CH - OTs---------------------------------- , I

c 6h 5 c h 3

c thc hin trong cng iu kin l rt nhanh, nhng khng ph thuchn vo nng ion axetat. C c h ca phn ng l g?

c) ng phn lp th n dn n tosylat threo. 1v tosylat rythro 1trngphn ng ny?

, d) Eng phn lp th no dn n tosylat threo v tosylt ery thro 1nu

iguyn t cacbon mang nhm tosyl s mang nhm C2H5thay cho CH}.

a) Phn ng ax eto gii nh sau:

(CH3)3 - c - c h - OTs a (CH3)3 - c - CH - OAc + TsO -I I

CH3 g h 3

tc ca s thay th i nhn khng ph thuc nng on axetat, l phn

ng SNj. S kin ny c xc minh bi:- M i trng ioii ha! ; - S solvat ha cc ion c to thnh bi nc lm tng tc phn ng.

Caeb ocation c to thnh' (giai on ch m ca qu trnh thay th) c th chus sp xp li 12 bi s di chuy n ca nhm m etyl

(CH3>3 c - CH- OTs -OTS H3Csr H3C - C - +CH - CH3

3

h 3C \ / C H 3'+c - CH

h 3c ^ c h 3

l s sp xp; li WAGNER - MEERWEIN.

Cacbocation ca s chuyn v, bc III tht s bn. Ngi ta thu c haisn phm axeto gii.

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83/394

>)Trong trng hp ngi ta i t tosylat:H

\H,c2 - c - CH - CH:

s ' Ih 5c 6 1 Ts

c ch vn l SN| v cc ion axetat khng tham gia vo phng trnh tc. Nhng:

- S hin d in v tr a ca nhm tosyl ca pheny l lm giu in t

- S gia tng mnh tc phn ng thch hp cho s thay th vi s thamgia ca nhm gn ( y l nhm phenyl). .

c) Ty theo s tn cng ca AcO ~ mang trn nguyn t C| v c 2, tosylthreo /(1) dn n axetat threo d(2) hay axetat threo /(3) ng phn v tr cach t trc.

H v OTs 'HH5C2 I g~/ - OTs . _ ^ C.1 - '2 c

/ , "' H>c; . 'H'

t h reo / ( l ) AcO ' trn i I AcO trn 2

AcO. *CH3 H OAc

, c> H^ w c . . * < / ;

. H *cf . ; ;; H5C H

hreo d (2) threo /(3 )

Trong cng iu k in, tosylt erythro /t o hai axe tat threo ng phn v trv ln lt dv /(2) v (3).

H , OTs H-v ^G H H s C a f e j v , 2 / -cm J ; c ' - 2c C h

, / C H5C2HsC


84/394

d) Trong trng hp ny khi i t ng phn threo / ngi ta qua mi ion

c cu i xng, s tn cng ng u trn 1 v 2 dn n axetat threo iritquang ha dv /. Trong trng hp ca ng phn erythro /, ion c cu trung

ian khng cn i xng na nhng s tn cng trn 1 v 2 to mt hp cht duynht l ery thro /

Clpro-1 dtpro-2 metylr2 butan c iu ch (trong tuen) bi midu

natri. Ngi ta thu c hai sn phm c cng in si v trong ph IR c shn-din ca giao ng Uc=c- Ngoi ra ph RMN thc hin trn hn hp chophp th y r ng mt trong hai sn phm ch c mt pro ton vinyl v ci khc chai. Sn phm ch c mt proton vinyl chim khong 5% hn hp. Mt khc s

to thnh gc kp tm thi r rng trong RPE. Xc nh hai sn phm v chobi t c ch phn ng.

AcCU axetat threo d, 1

6.1

h 3c xC = CH2 (95%)H3C \

CD - CH2 -Ci/

h 5c 2/'C = CHD (5%)

H5C2 .;

H ,c



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85/394

sn phm c xem xt cho hai phn ng kh cnh tranh nhau. Cc iukin phn ng (mi trng t ion ha) khng phi l iu kin ca s d gii>c - X coi nh xc nh n l gc trung gian.

Ngc li NH2 l baz mnh c kh nng bt proton. S kin ngi tanhn c trung gian hai gc (un.badic intermdiaire) ch rng hai ln kt

ln lt b b gy; hai lin kt ny ch c th l c - X v c - H ca nguyn tcacbon cu l Trc h t lin kt c - H b b gy, nu khng s C gii ca c - Xlo eaebocation.

H3C \ H3C \C D - C H 2 - X + N H2 CD - CH - X +N H 3

MjCX.CD - CH - X ----- CD - CH + X -

H5C2 h , c / "

'Ci cn g xy ra s di chuyn ca dteri

\ __ \C D - ---- c = CDH

^ v : /

y xy r phn ng kh a (s kh XH trncng ngu yn t eacbon). Cch ca s to thnh sn phm khng c dteri l c ch c in E 2.

. . ^ INH2

H3 ^ a c ^ HH *- n h 2d t X - + H3C' ' c = c h 2

H5C2 \ H5C2

S tn cng, ny trn nguyn t cacbon p


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87/394

CH C H i - C H C H 2 ^ O H

(60%)h 3c c h 3

/ SN- CH3 -CH2 - +-C

( H O ' )

CH

E,

CH3- CH = cJ \ c n 3" c h 3

(32%) + CH3 - CH2 - c =.CH2 (.8%)c h 3

S d ly ca c - Br s c u i bi s ba ln th (cacbocation c tothnh s bn) v thit lp g iai on chm n ni s thay th cng nh s kh.

- S thay th trri nguyn t cacbon a tng kh nng xy ra SNi v E|vi SN2v E2. .

' r S thy th trn nguyn t cacbon p, ngha s m nhn h ca cc gc

Ri,;R-2i Rs lu i Ej so vi SN.|. Th t, s gim lp th chb php s tio

trc 't din sau s tn cng ca cht i nhn ( y l HO ~). Trong trng h.pcloro tertiopentyl, cc gc khng kh ln v b thay th cho s kh chim uth.

S nh hng ca. s kh E lun .c thc hin u th trn anken nhiu

nhm th .hn. Thc t proton ch ra m t cch c u th (giai on 2. ca phnng) t nguyn t cacbon n b kirri hm. r

b) ~ Trng tB u-B r, b nhm mety l t l vng vu nhau v n

cacbocation tng ng to ra d dng, n s lin k t vi HO ~ to s thay th.Phn trm ca SN] s tng hn trong trng hp ca tPt-Br.

- Ngc li trong dimetyl-2,2 etyl-3 clro-3 pentan, nhng nhm th cnguyn t cacbon a rt ln v b km hm m nh trong sn phm n. Sau khi

,nhn cacbocation, s kh ca proton cho php g im s g b lp th. '

R.Vcacbocation R2 c + khi R|, R2, R3ln b hy b khi nguyn t c ly li cu

r /

(3) 8%

(2) 32%

9,0



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88/394

h 3c

IB 11

/

c = CH - CH^

S thay th i nhn thc t khng xy ra trong trng hp cui.

6.3

a) Dimety 1-3,4 bromo-3 hexan erythro d c ch ha vi EtONa trongEtOH, to hn hp sn phm. Pip sc k th hi cho php pht hin bn sn

phm mi c sp xp theo:

- Hn hp lm lch hhg m t phng phn cc ca nh sng .

- Ph IR cho ph p pht hin chc ete v s hion din ca ni i. Cho bit

nh ch t ca sn phm c to thnh v c ch c c phn ng khc nhau xy ra.

b) Bromo-2-m etyl~3-pen tan th re o c ch ha vi EtONa trong EtOH tohn hp hai sn phm lm lch mt phng phn cc ca nh sng ngi ta

pht hin cc dao ng ca lin kt vc=c v V(_ o C ). Tnh cht ha hc lp th

ca cc sn p hm th c l g?

Cacbo cation c to thnh, c s quay chung quanh lin kt c - c t

khng c tnh lp th c bit. ' '

H+ H3C \ / C H 3 h 3c ^ / C 2h 5Ex: c - c ; + c - Ch 5c 2^ ' ^ c 2h 5 h 5c 2^ ^ c h 3

Hai sn phm.ng phn lp th cis-trans ny iic phn tch bng CPV..

SNi + --P-> m t trng nhng th cii. quang threo v mt trong nhng th

i quang eryth ro ca: : '

EtOH

EtO -

91



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89/394

h 3c ^ * / C H 3c - c

H5C2 O E t^ C2H5

Hai mi tng ng t c phn tch bng CPV.

b) CH3 - CHBr -CH - C2H5 S N , CH3 - CH - CH - C2H5I *" I I

CH3 Et CH3--------------- i Eo

CH3 - CH = c/ C 2h 5

c h 3

Ha hc lp th: SN2to s nghch o cu hnh tr n Ca-

(- mt trong nhng th i quang erythro)

E2(-* dn xut cis)

Et O

Nhm th ln hn trn cacng pha vi nhm th ln hn trn Cp.

6.4

a) Cho bi t trc tin tnh cht v ha hc lp th ca nhng sn phm thuc nu ta ch bin nhng hp cht sau trong dng dch baz:

b) Cng cu hi

tBu

c).Cng cu hi vi hp cht

92



B

I

D

N

GT

O

N

-

L

-

H

A

C

P

2

3

1

0

0

0

B

T

R

N

H

N

G

O

T

P

.

Q

U

Y

N

H

N

W.DAYKEM

bÀi tẬp chuyÊn hÓa hỮu cƠ - huỲnh bÉ (nguyÊn vỊnh) 395 pages

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