作者:Takeshi Sugai、Hajime Ikeda、Hiromichi Ohta
DOI:10.1016/0040-4020(96)00374-2
日期:1996.6
analog, (2S,3S)-2-ethoxy-3,4,5,6-tetrahydro-2H-pyral-3-ol were prepared by biocatalytic optical resolutions. Lipase-catalyzed enantioselective acetylation of the racemate in organic solvent worked well with a high enantioselectivity. Pseudomonas cepacia lipase was most effective (E = 11–17) for the kinetic resolution. Under the optimized condition, the products, (2R,3S)-2-allyloxy-3,4,5,6-tetrahydro-2H-pyran-3-ol
用于不对称添加有机金属的手性助剂前体的对映体及其类似物(2 S,3 S)-2-乙氧基-3,4,5,6-四氢-2 H-吡喃-3-醇均是通过生物催化光学拆分制备。在有机溶剂中,脂肪酶催化外消旋体的对映选择性乙酰化效果很好,对映选择性很高。假单胞菌洋葱脂酶对动力学分辨率最有效(E = 11-17)。在优化条件下,产物(2 R,3 S)-2-烯丙氧基-3,4,5,6-四氢-2 H-吡喃-3-醇和(2 S,3 S)-2-乙氧基ee大于97%的类似物以31–45%的产率获得,转化率为52–62%。对映体(2 S,3 R)-2-烯丙氧基化合物通过两种方法固定。在部分对映异构体富集的底物上重复进行脂肪酶催化的乙酰化反应,可得到具有高ee(97%)的乙酸酯。一锅反应中新开发的双分辨程序也很成功。在这种情况下,通过两个步骤的视在E值高达71。