`CH_(3)CHO` REACTS with HCN to yield a racemic mixture `CH_(3)-OVERSET(C_(2)H_(5))overset(|)underset(OH)underset(|)(C)-HandH-overset(C_(2)H_(5))overset(|)underset(CH_(3))underset(|)(C)-OH` are enantiomers `CH_(3) - CH = NOH` exhibits geometrical isomerism