Diastereoselective Reduction of α-Keto Amides Having <i>trans</i>-2,5-Disubstituted Pyrrolidine as a Chiral Auxiliary

Abstract

Abstract The reduction of α-keto amides derived from (2R,5R)-trans-2,5-bis(methoxymethoxymethyl)pyrrolidine [(R)-BMOMP, 1] with LiBEt3H or KBEt3H proceeded with high diastereoselectivity (up to 99% ds) to afford the corresponding α-hydroxy amides in good yields. The additive effect of crown ethers or metallic salts on the stereoselectivity was also examined.