反应详情

Cis-methyl 2-(4-fluorophenethyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (1.4 g, 4 mmol) was subjected to chiral preparative HPLC (Column: Chiralpak AD (250×20), 5 μm particle size, mobile phase: Heptane/EtOH 80/20, flow rate 18 mL/min) to yield (2S,4S)-methyl 2-(4-fluorophenethyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (582 mg, 42%), Chiral purity 99.9% ee, Optical rotation [α]D20=+51.6 (acetonitrile, c=1) and (2R,4R)-methyl 2-(4-fluorophenethyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (676 mg, 48%), Chiral purity 99.4% ee, Optical rotation [α]D20=−45.0 (acetonitrile, c=1)