2-methoxy-4-(3,3,5-trimethyl-2,4-dioxopyrrolidin-1-yl)benzonitrile 、 L-SELECTRIDE tetrahydrofuran 以in the same manner as in Example 5, the title compound was obtained as a colorless solid (yield: 75 mg, 74%)的产率得到rac-4-[(4R,5R)-4-hydroxy-3,3,5-trimethyl-2-oxopyrrolidin-1-yl]-2-methoxybenzonitrile