organi ii mechanisms
DESCRIPTION
mecanismos em química orgânicaTRANSCRIPT
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Organic II Mechanisms 1. Alkadienes a. HX addition to a conjugated diene:
b. General Diels-alder cycloaddition reaction(Diene must be in cis configuration):
2. Aromatics a. Electrophilic aromatic substitution (halogenation):
b. Electrophilic aromatic substitution (Nitration):
c. Electrophilic aromatic substitution (Sulfonation):
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d. Electrophilic aromatic substitution (Alkylation):
e. Electrophilic aromatic substitution (Acylation):
f. Nucleophilic substitution reaction of aryl halides with EWG (Meisenheimer complex; ortho/para only):
g. Preparation of phenol from halobenzene via benzyne:
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3. Alcohols a. 3o alcohol- acid catalyzed dehydration:
b. 2o, 3o alcohol dehydration with POCl3:
c. 3o alcohol to alkyl halide using HX (X= Cl, Br, I):
d. 1o, 2o alcohol to alkyl halide using SOCl2:
e. 1o, 2o alcohol to alkyl halide using PBr3:
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4. Ethers a. Acid catalyzed synthesis of symmetrical ethers (1o alcohols only):
b. Williamson ether synthesis (1o or 2o RX only; can be intramolecular):
c. Alkoxymercuration of alkene to form ethers:
d. Acidic cleavage of ethers(1o and 2o ethers; HI or HBr only):
e. Claisen rearrangement of an allyl aryl:
f. Alkenes with peroxyacid:
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g. Alkene with X2/H2O and a strong base:
h. Acid-catalyzed epoxide ring opening(X=F, Br, Cl or I):
i. Base-catalyzed epoxide ring opening (Sn2) :
5. Aldehydes/Ketones a. Nucleophilic addition to a ketone or aldehyde:
b. Grignard(RMgX) addition to a ketone or aldehyde:
c. Hydride addition to a ketone or aldehyde:
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d. 1o amine addition to a ketone or aldehyde (Imine formation):
e. 2o amine addition to a ketone or aldehyde (Enamine formation):
f. Wittig Reaction:
g. Conjugate addition of a nucleophile to an ,-unsaturated aldehyde or ketone:
Nu=RNH2, R2NH, R2CuLi(R:-), -:CN
enolate
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6. Carboxylic Acids/Nitriles a. Carboxylation of Grignard reagent to prepare carboxylic acids:
b. Nitrile with an organometallic reagent:
7. Carboxylic Acid Derivatives a. Conversion of carboxylic acid into acid chloride:
b. Conversion of carboxylic acid into acid anhydride:
c. Conversion of carboxylic acid into an ester ( 2 ways):
Sn2 Route
Fischer esterification
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d. Conversion of carboxylic acid halides into carboxylic acids, esters, amides, aldehydes, ketones, or alcohols: (Y= Cl, Br)
e. Conversion of carboxylic acid anhydrides into carboxylic acids, esters, amides, or alcohols: (Y= O2CR)
f. Conversion of esters into carboxylic acids, amides, or alcohols: (Y= OR)
g. Conversion of amides into carboxylic acids: (Y= NH2, NHR, NR2)
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8. Carbonyl -Substitutions a. Base catalyzed enolate formation:
b. Acid catalyzed enol formation:
c. -halogenation of a carbonyl (aldehydes/ketones only):
d. Hell-Vollhard-Zelinski (HVZ) reaction (carboxylic acids only):
e. Haloform reaction (methyl ketones only):
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f. Alkylation of enolates, esters and ketones (Sn2 reactions):
g. alkylation of nitriles:
h. Malonic ester synthesis:
i. Acetoacetic ester synthesis:
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9. Carbonyl Condensations a. General carbonyl condensation reaction:
b. Base catalyzed dehydration of an aldol:
c. Acid catalyzed dehydration of an aldol:
d. Intramolecular aldol condensation reaction:
e. Claisen condensation reaction:
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f. Dieckmann cyclization (intramolecular Claisen condensation):
g. Michael addition reactions:
h. Stork enamine reaction:
Reverse of enamine formation yields:
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i. Robinson annulation reaction (Combination of Michael rxn 1st, followed by an intramolecular Aldol rxn):
See intramolecular aldol rxn above for the mechanism of part 2.
10. Amines a. Azide synthesis of a primary amine:
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b. Gabriel synthesis of an amine:
c. Reductive amination of aldehydes and ketones: