ucleophilic a substitution 9...2019/08/08 · chapter 21, carboxylic acid derivatives l9-1 chem 8b,...
TRANSCRIPT
Chapter 21, Carboxylic Acid Derivatives
L9-1
CHEM 8B, Lecture 9 Carboxylic Acid Derivatives: Acid Chlorides, Anhydrides, Esters, & Amides - Nomenclature - Nucleophilic Acyl Substitution (NAS) - Addition of Grignards – another combo mechanism (NAS + Nuc Add’n)
NUCLEOPHILIC ACYL SUBSTITUTION (NAS)
REACTIVITY SERIES (TOWARD NAS)
9 2I
not always0 LG Hd
itonl.ooqfcwfatgi.dk
it
i ii
ROH OR poorLG
ROH LG
NR not LGHNRz aHNREOKLGRcorltkasteact.ve
Chapter 21, Carboxylic Acid Derivatives
L9-2
NOMENCLATURE CARBOXYLIC ACIDS NITRILES butanoic acid benzoic acid butanenitrile
ACID CHLORIDES butanoyl chloride benzoyl chloride
ANHYDRIDES butanoic anhydride benzoic anhydride
Butanoic benzoic anhydride ESTERS butyl butanoate butyl benzoate phenyl benzoate
AMIDES Butanamide N-methyl-N-phenylbenzamide
CARBONYL OUTSIDE A RING Cyclopentane carbaldehyde cyclopentane carboxylic acid
methyl cyclopentane carboxylate N-ethyl cyclohexane carboxamide
7 4
NCNO
7 a
symmetric o
whobutyl
IEEE on EIKOphtoph
Effidemide YEH's zoamide
5 I 5 l
ester
of pit 31mF
back 1113
Chapter 21, Carboxylic Acid Derivatives
L9-3
NUCLEOPHILIC ACYL SUBSTITUTION (NAS)
Acidic NAS Mechanism - Fischer Esterification
- Try on your own: Acidic amide hydrolysis
Neutral NAS Mechanism (just add water!) - Acid Chloride Hydrolysis
- Try on your own: ester from acid chloride
OH
O+
HO
H2SO4 (aq)
D O
O+ H2O
5 aI
protofansfer
acidic PT9copyltranslate
fromL8 FT n
Ee i NASI 2
ii ii iig
902 U GPT
H i PiggyB
qii ii
Chapter 21, Carboxylic Acid Derivatives
L9-4
Basic NAS Mechanism - Amides from Acid Chlorides
- Try on your own: Basic hydrolysis of esters
Imagine the possibilities!
Fill in the reagent(s) needed to complete each transformation above.
Cl
O
NaOH
H2NMe
NHMe
O
OH
O
OCH3
O
NHCH3
O
Cl
O
O
O
OH
O
OCH2CH3
O
N(CH3)2
O
O
OH
O
Nucleophilic Acyl SubstitutionReactions
OH
O
OOH O_0
odfqg aHzNMe
jNMe 9
HooIY oµeV o_0
Liter AaoHNMe
H o_O t CHIH0nucrG i eoI
mostreactive
go.fi EreHogreat
H2Ohydrolysis
H2O
CH3OHAtois HOT H2O
CatalystHt orOOHHzNCH3 excess
DCL HNMer H2ODcatalyst
specialreagent amide Ht or00A
more iffy
Chapter 21, Carboxylic Acid Derivatives
L9-5
Adding Grignards & Hydrides to Acid Derivatives
TMT – Chapter 17 – addition to esters
Grignards and LAH add to (almost) all the acid derivatives to make the same product!!!
O
O
ethyl acetate
1. PhMgBr
2. H3O+
1. LiAlH4
2. H3O+
9 to
gy AIG
µ f
pyoaldehyde ketoneµ0
E Eai
NRas
Chapter 21, Carboxylic Acid Derivatives
L9-6
Making Ketones with Mr. Grignard and Mr. Gilman (we missed you)
Ketones from nitriles (Chapter 20)
Ketones from acid chlorides
SUMMARY pilgBr H HO arDuc LAHlings gtfo arXat
ofRacaciR
NAS Try on your ownHE
Huo
racyH2
s joy tHzNHz T
E mme sc i ne siotJmlGoekItii4ester a
Cephile q
Gsc
gNaootnuaE IootcHs0H
G asc