Triethylamine (1.32 g, 13.05 mmol) and formic acid (350 mg, 7.82 mmol) were added to a chlorobenzene solution (10.0 ml) of RuCl[(R,R)-TsDPEN](p-cymene) complex (8.8 mg, 0.01 mmol) and ethyl 2-acetylamino-3-oxooctadecanoate (1.00 g, 2.61 mmol) synthesized in the same method as Example 1. After the reaction mixture was stirred for 3 days at 40° C., water (10 mL) was added thereto and separation operation was carried out at 40° C. to obtain the organic layer. It was confirmed by comparative analysis of the organic layer with sample product using HPLC that the organic layer contained 0.96 g of the title compound was contained (yield: 96%). Further, anti-form:syn-form was 98:2 and the optical purity of the anti-form was 97% ee.
