( vii ) Cannizzaro reaction Aldehydes which do not have any α – hydrogen atom , undergo self oxidation and reduction ( disproportionation ) reaction on treatment with concentrated alkali .
( viii ) Electrophilic substitution reaction Aromatic aldehydes and ketones undergo electrophilic substitution . Carbonyl group shows + R effect , therefore acts as a deactivating and meta directing group .
( ix ) Baeyer- ViLLiger oxidation With Caro ‟ s acid ( H2SO5 ) or per benzoic acid ( C6H5CO3H ) or peracetic acid ( CH3CO3H ) aliphatic ketones give ester .
( xi ) Knoevenagel reaction It involves condensation between active methylene group and , carbonyl groups in the presence of base .