2 From carbonyl compounds
(i) By reduction of aldehydes and ketones: Aldehydes and ketones
are reduced to the corresponding alcohols by addition of
hydrogen in the presence of catalysts (catalytic hydrogenation) The usual catalyst is a finely divided metal such as platinum,
palladium or nickel It is also prepared by treating aldehydes
and ketones with sodium borohydride (NaBH4) or lithium
aluminium hydride (LiAlH4)