Alcohols

Description

Alcohols are a functional group consisting of an ${-}{\rm{OH}}$ attached to an sp³-hybridized carbon. The nomenclature of alcohols includes common names for smaller and simpler alcohols and IUPAC nomenclature for larger and more complicated alcohols. Alcohols have very large intermolecular forces because of dipole-dipole forces and hydrogen bonding. Phenols are significantly more acidic than straight-chain alcohols because of the resonance structures that exist for the conjugate base.

There are many synthetic methods to prepare alcohols. Alcohols are formed by substitution reactions, hydration of alkenes, reduction of carbonyls, or the reaction of carbonyls with organometallic reagents, such as Grignard reagents. Syn- or anti-diols are derived from alkenes, and other diols are synthesized from reduction of dicarbonyls. Reactions of alcohols include conversion to halides, dehydration to alkenes, and oxidation to carbonyls.

At A Glance

• Alcohols are a functional group consisting of an ${-}{\rm{OH}}$ attached to an sp³-hybridized carbon. In IUPAC nomenclature, alcohols are indicated by changing the suffix from -ane to -anol. A number indicates the location of the alcohol. Alcohols have priority for numbering over all other groups except for carbonyls (ketones, aldehydes, carboxylic acids, etc.).
• Alcohols exhibit both dipole-dipole forces and hydrogen bonding. Phenols are significantly more acidic than alcohols because of resonance.
• Alcohols are prepared by substitution reactions or via the hydration of alkenes using three different reagents that produce different regiochemistry and stereochemistry.
• Alcohols are prepared via the reduction of carbonyls with LiAlH₄ or NaBH₄, the reaction of carbonyls with organometallic reagents, and the reduction of dicarbonyls.
• Alcohol reactions include the conversion of alcohols to halides, dehydration of alcohols to alkenes, conversion of alcohols to sulfonate esters, and oxidation of alcohols to carbonyls.