Chemistry > Alcohols, Phenols and Ethers > 4.0 Preparation of Alcohol
Alcohols, Phenols and Ethers
1.0 Alcohols
2.0 Classification of alcohols
3.0 Physical properties of the alcohol
3.0 Physical properties of the alcohols
4.0 Preparation of Alcohol
4.1 By hydrolysis of alkyl halide
4.2 Acid catalysed hydration of alkenes
4.3 Oxymercuration Demercuration
4.4 Hydroboration-oxidation
4.5 Hydroxylation of alkenes
4.6 From organometallic compounds
4.6 Reduction of Esters
5.0 Grignard reagent
5.1 Reaction & Mechanism
5.2 Product of Grignard reagent
5.3 Planning a Grignard synthesis
5.4 Restriction of the use of Grignard reagents
6.0 Chemical properties of alcohols
6.1 Acidic character
6.2 Dehydration
6.3 Reaction with phosphorus trihalide or thionyl chloride
6.4. Reaction with hydrogen halide
6.5 Oxidation of Alchols
7.0 Tests for Alchols
8.0 Ethers
9.0 Chemical Properties of Ethers
10.0 Aryl Ethers
11.0 Epoxides
12.0 Phenols
13.0 Preparation of Phenol
14.0 Physical Properties of Phenol
15.0 Chemical properties of phenols
4.6 Reduction of Esters
4.2 Acid catalysed hydration of alkenes
4.3 Oxymercuration Demercuration
4.4 Hydroboration-oxidation
4.5 Hydroxylation of alkenes
4.6 From organometallic compounds
4.6 Reduction of Esters
5.2 Product of Grignard reagent
5.3 Planning a Grignard synthesis
5.4 Restriction of the use of Grignard reagents
6.2 Dehydration
6.3 Reaction with phosphorus trihalide or thionyl chloride
6.4. Reaction with hydrogen halide
6.5 Oxidation of Alchols
Like many organic compounds, esters can be reduced in two ways:
(a) by catalytic hydrogenation using molecular hydrogen, or
(b) chemical reduction.
In either case, the ester is cleaved to yield (in addition to the alcohol or phenol from which it was derived) a primary alcohol corresponding to the acid portion of the ester.
Hydrogenolysis (cleavage of hydrogen) of an ester requires more severe conditions than simple hydrogenation of (addition of hydrogen to) a carbon-carbon double bond. High pressures and elevated temperatures are required: the catalyst used most often is a mixture of oxides known as copper chromite, of approximately the composition $CuO.CuCr_2O_4$.
For example,
Chemical reduction is carried out by use of sodium metal and alcohol, or more usually by use of lithium aluminum hydride.
For example:
