Chapter 20: Carboxylic Acids

IR spectroscopy

C=O stretch and O-H stretch

C=O stretch

1710cm (as the dimer)

O-H stretch

2400-3600 (very broad)

1H NMR spectroscopy

alpha protons and O-H

alpha protons chemical shift

2.0-2.5

O-H protons chemical shift

10-13 (broad, exchanges with D2O)

13C NMP spectroscopy

160-180ppm

carbonyl C has ___ chemical shift than ____

lower; aldehydes and ketones

why does carbonyl C have lower chem shift

shielding effects of nonbonding e- pairs on carboxylate O

first way to synthesize carboxylic acid

oxidation of primary alcohols and aldehydes

second way to synthesize carboxylic acids

oxidation of alkyl benzene containing benzylic hydrogen

third way to synthesize carboxylic acids

carboxylation of Grignard reagent

oxidation of primary alcohols reagent

HaCrO4, H2O, acetone

oxidation of aldehydes reagents

1. Ag2O, H2O, OH-

2. H30+ (workup)

oxidation of alkyl benzene containing benzylic hydrogen reagents

1. KMnO4, OH-

2. H3O+

Fischer esterification reagents

carboxylic acid and alcohol produces esters

diazomethane esterification reagents

carboxylic acid, diazomethane (:CH2 - N+= N:)a, and ether produce ester

acid chlorides reagents

carboxylic acid, (SOCl2 OR PCl5) to form acid chloride (Cl instead of OH)

sulfonyl chloride reagents

sodium salts, PCl5 to make sulfonyl chloride

aromatic sulfonyl chloride reagents

1. benzene (w/ H), chlorosulfonic acid, forms benzenesulfonic acid and HCl

2. benzenesulfonic acid and excess chlorosulfonic acid, relplace OH in sulfonic acid with Cl, and OH goes to chlorosulfonic acid to make sulfuric acid

synthesizing anhydrides reagent

dehydrating! (ANhydride)

conversion to anhydride all reagents