Study Set Content:
Alcohol Formation
- Nucleophilic Addition of Hydride Reagents: Reduction
- Nucleophilic Addition of Grignard Reagents
Nucleophilic Addition of Water:
Hydrate formation
Nucleophilic Addition of Alcohol:
Acetal Formation
Nucleophilic Addition of Amines:
Imine formation
Alcohols can be prepared by
- reduction of carbonyl compounds
- Aldehydes reduced using to yield 1° alcohols
Sodium borohydride (NaBH4)
Ketones are reduced in using similar methods to give
- 2° alcohols
Addition of Grignard Reagents, RMgX
Aldehydes give
- 2°alcohols
Addition of Grignard Reagents, RMgX
Ketones give
- 3° alcohols
Nucleophilic Addition of H2O:
Hydration
Aldehydes and ketones react with water to yield
1,1-diols or geminal (gem) diols.
Latin geminus, meaning
twin
Hydration reaction is
reversible
can eliminate water
gem diol
Nucleophilic Addition of Alcohols:
Acetal Formation
Aldehydes and ketones react reversibly with 2 equivalents of alcohol in the presence of an acid catalyst to yield
- acetals R2C(OR')2
if derived from a ketone its called
ketals
- are valuable to organic chemist because they can serve as protecting groups for aldehydes and ketones.
Acetals
A ketone reacts with an alcohol in the presence of acid to yield an
acetal
To find the product, replace the oxygen of the ketone with two
-OCH3 groups from the alcohol.
