Why teritay alcohol cannot be made by hydrogenation of aldehydes or ketones?

Answer 1

Ter. alcohols are those in which alpha carbon (carbon bearing halogen atom) is attached to three other carbon atoms, in aldehyde there is only one and in ketones there are two carbons attached to alpha carbon so by hydrogenation aldehydes may be converted into primary alcohols and ketones into secondary alcohols so preparation of ter. alcohols is not possible. however ketones with Grignard's reagents may produce tertiary alcohols.