Diastereoselective aldol reaction of N-tert-butanesulfinyl imidates under typical hard enolization conditions is reported. Potassium bis(trimethylsilyl)amide (KHMDS) effectively promotes the aldol reaction of alpha-aryl- and alpha-alkyl-substituted imidates, providing anti-aldol adducts in high yields with good to excellent diastereoselectivities. In the case of alpha-aryl imidates, high conversion depends on adding trimethylsilyl chloride (TMSCI) to the reaction,, Mixture. In the presence of a suitable Lewis acid, cyclohexanone is a good electrophile in the aldol reaction of imidates.