外消旋体 p-CH3o-C6H4CHOCOCH3 二嗎烷 p-CH3O-C6H4CHOH C6H5 6n5 Ch cooh Br OH Ph-ch-CH? CH3OH Ph-CH-CH3 27%构型转化 73%外消旋化C6H5 p CH3O C6H4 CHOCOCH3 * p CH3O C6H4 CHOH C6H5 * + CH3COOH H2O- 二噁烷 外消旋体 Br Ph CH CH3 * OH Ph CH CH3 CH3 OH * 27%构型转化 73%外消旋化