反应详情

Trans-methyl 2-(2-fluorobenzyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (468 mg, 1.4 mmol) was subjected to chiral preparative HPLC (Column: Chiralcel OJ (250×30), 5 μm particle size, mobile phase: 20% EtOH in CO2 (175 bar), flow rate 130 mL/min, temperature 40° C.) to yield (2S,4S)-methyl 2-(2-fluorobenzyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (199 mg, 43%), Chiral purity 98.5% ee, Optical rotation [α]D20=+28.8 (acetonitrile, c=1) and (2R,4R)-methyl 2-(2-fluorobenzyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (185 mg, 40%), Chiral purity 99.7% ee, Optical rotation [α]D20=−28.9 (acetonitrile, c=1)