Classification of Alcohols

Alcohols are organic compounds bearing a hydroxyl (-OH) functional group. Based on the NUMBER of -OH groups, alcohols are classed as monohydric (one -OH, e.g. ethanol CH3-CH2-OH), dihydric (two -OH groups, glycol), trihydric (three -OH groups, glycerol) and, more generally, polyhydric (many -OH groups, e.g. sorbitol). Based on the CARBON to which -OH is attached, alcohols with -OH on an sp3-hybridised carbon are classed as PRIMARY (-OH on a carbon bonded to one other carbon, e.g. ethanol), SECONDARY (bonded to two other carbons, e.g. propan-2-ol) and TERTIARY (bonded to three other carbons, e.g. 2-methylpropan-2-ol). Alcohols with -OH on an allylic carbon (next to a C=C, e.g. prop-2-en-1-ol) or a benzylic carbon (next to an aromatic ring, e.g. phenylmethanol) are named separately. -OH directly on an sp2 carbon of a C=C (vinyl alcohol, CH2=CH-OH) or directly on an aromatic ring is NOT classed as an alcohol at all -- the latter is a phenol. W …