Stereoselective addition reaction of organometallics to α-keto amides having (S)-2-methoxymethylindoline

Abstract

The stereocontrolled addition of organometallics to carbonyl compounds possessing chiral auxiliary is a highly useful synthetic operation for the asymmetric synthesis. Diastereoselective addition of several organometallics to the chiral $\alpha$-ketoamides, prepared from $\alpha$-keto acid and new chiral (S)-2-methoxymethylindoline, afforded optically active $\alpha$-hydroxy amides. Organotitanium reagents resulted in best results up to $>96\%$ de. The ratio of diastereomers was determined by the chiral column (CHIRAL CELL OD) chromatography and $^1H$ NMR analysis (300 MHz).