chapter_21LG

chapter_21LG - Chapter 21 Carboxylic Acid Derivatives...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chapter 21 Carboxylic Acid Derivatives Organic Chemistry , 6 th Edition L. G. Wade, Jr. Carboxylic Acid Derivatives • Acyl group bonded to Y, an electronegative atom or leaving group • Includes: Y = halide (acid halides), acyloxy (anhydrides), alkoxy (esters), amine (amides), thiolate (thioesters), phosphate (acyl phosphates). All can be converted to the carboxylic acid by acidic or basic hydrolysis. • Esters and amides common in nature. Chapter 21 3 Naming Esters • Esters are named as alkyl carboxylates. • Alkyl from the alcohol, carboxylate from the carboxylic acid precursor. CH 3 CH 2 OH HO C O CH 3 H + + + H 2 O CH 3 CH 2 O C O CH 3 ethanol ethyl alcohol ethanoic acid acetic acid ethyl ethanoate ethyl acetate => Chapter 21 4 Name These CH 3 CHCH 2 OCCH 3 CH 3 O HCOCH 2 O isobutyl acetate 2-methylpropyl ethanoate benzyl formate benzyl methanoate => Chapter 21 5 Cyclic Esters • Reaction of -OH and -COOH on same molecule produces a cyclic ester, lactone. • To name, add word lactone to the IUPAC acid name or replace the - ic acid of common name with - olactone . O O H 3 C CH 3 4-hydroxy-2-methylpentanoic acid lactone α-methyl- γ-valerolactone => Chapter 21 6 Amides • Product of the reaction of a carboxylic acid and ammonia or an amine. • Not basic because the lone pair on nitrogen is delocalized by resonance. H C O N H H H C O N H H _ + Bond angles around N are close to 120 ° . => Chapter 21 7 Classes of Amides • 1 ° amide has one C-N bond (two N-H). • 2 ° amide or N-substituted amide has two C-N bonds (one N-H). • 3 ° amide or N,N-disubstituted amide has three C-N bonds (no N-H). => Chapter 21 8 Naming Amides • For 1 ° amide, drop - ic or - oic acid from the carboxylic acid name, add - amide . • For 2 ° and 3 ° amides, the alkyl groups bonded to nitrogen are named with N- to indicate their position. CH 3 CHC N O CH 2 CH 3 CH 3 CH 3 N-ethyl- N ,2-dimethylpropanamide N-ethyl- N-methylisobutyramide => Chapter 21 9 Cyclic Amides • Reaction of -NH 2 and -COOH on same molecule produces a cyclic amide, lactam. • To name, add word lactam to the IUPAC acid name or replace the - ic acid of common name with - olactam . N O CH 3 H 4-aminopentanoic acid lactam γ-valerolactam => Chapter 21 10 Nitriles •-C ≡ N can be hydrolyzed to carboxylic acid, so nitriles are acid derivatives. • Nitrogen is sp hybridized, lone pair tightly held, so not very basic (p K b about 24). => Chapter 21 11 Naming Nitriles • For IUPAC names, add - nitrile to the alkane name. • Common names come from the carboxylic acid. Replace - ic acid with - onitrile . CH 3 CHCH 2 CH 2 CH 2 CN Br 5-bromohexanenitrile ∂-bromocapronitrile C N Cyclohexanecarbonitrile => Chapter 21 12 Acid Halides • More reactive than acids; the halogen withdraws e- density from carbonyl....
View Full Document

This note was uploaded on 04/27/2008 for the course CHEM 242 taught by Professor Zhan during the Spring '08 term at Tulane.

Page1 / 66

chapter_21LG - Chapter 21 Carboxylic Acid Derivatives...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online