Asymmetric reduction of some 3-keto esters (6, 8, and 11) to 3-hydroxy esters (7, 9, and 12) with various chiral reducing agents was investigated. The products (9 and 12) were converted to methyl (2R, 3S)-3-(4-methoxy-phenyl)glycidate (2R, 3S-3), a key intermediate in the practical enantioselective synthesis of dilitazem (1).
研究了某些3-
酮酯(6、8和11)通过不同手性还原剂不对称还原为3-羟基酯(7、9和12)的过程。产物(9和12)被转化为甲基(2R, 3S)-3-(4-
甲氧基苯基)
缩水甘油酸酯(2R, 3S-3),这是在实际合成Diltiazem(1)的对映选择性合成中的关键中间体。