Optically active 2-hydroxymethyl-1, 4-dihydropyridines were obtained by lipase-catalyzed hydrolysis or transesterification of racemic materials. Chiral NB 818 and nilvadipine have been synthesized from chiral 2-hydroxymethyl-1, 4-dihydropyridine. On the other hand, chiral 1, 4-dihydropyridines obtained from prochiral substrates have been converted into (S)-NB 818 and (R)-nilvadipine via regioselective bromination of methyl groups under mild conditions.
通过
脂肪酶催化外消旋物质的
水解或酯交换反应得到光学活性的2-羟甲基-1,4-
二氢吡啶。手性 NB 818 和
尼伐地平是由手性 2-羟甲基-1, 4-
二氢吡啶合成的。另一方面,从前手性底物获得的手性 1, 4-
二氢吡啶在温和条件下通过甲基的区域选择性
溴化转化为 (S)-NB 818 和 (R)-
尼伐地平。