Discuss the preparation of aldehydes and ketones from alkenes.
Prepartion of aldehydes:
From acyl chloride (acid chloride):
Acyl chloride is hydrogenated over catalyst, palladium on barium sulphate. This reaction is called Rosenmund reduction.
From nitriles and esters:
Nitriles are reduced to corresponding imine with stannous chloride in the presence of hydrochloric acid which on hydrolysis give corresponding aldehyde.
Prepartion of ketones:
Treatment of acyl chlorides with dialkylcadmium gives ketone.
From benzene or substituted benzenes:
when benzene or substituted benzene is treated with acid chloride in the presece of anhydrous aluminium chloride, it afford the corresponding keton. This reaction is known as Friedel - crafts acylation reaction.