作者:Seiko Kimura、Ryoko Ehama、Kohei Inomata
DOI:10.1055/s-2002-31949
日期:——
Optically pure C2 -symmetric 4-cyclopentene-1,3-diol has been prepared in both enantiomeric forms from racemic (3aS*,4R*,7S*,7aS*)-3a,4,7,7a-tetrahydro-4,7-methano-1H-inden-1-one by employing lipase-mediated kinetic resolution as the key step. As a result, the known (3aS*,4R*,7S*,7aS*)-3a,4,7,7a-tetrahydro-4,7-methano-1H-inden-1-one is transformed into (1′S*,3′S*,3′aR*,4′S*,7′R*,7′aS*)- 2′,3′,3′a,4′,7′,7′a-hexahydro-3′-hydroxy-4′,7′-methano-1′H-inden-1′-yl benzoate, via stereo- and regioselective hydride reduction of epoxy ketone and sequential benzoylation, which is resolved under transesterification conditions in the presence of lipase. The hydride reduction of benzoate and acetate gives the corresponding chiral diols, which are further transformed into both enantiomers of C2 -symmetric 4-cyclopentene-1,3-diol via a retro-Diels-Alder reaction.
通过脂肪酶介导的动力学解析这一关键步骤,从外消旋(3aS*,4R*,7S*,7aS*)-3a,4,7,7a-四氢-4,7-甲桥-1H-茚-1-酮制备出了两种对映体形式的光学纯 C2-不对称 4-环戊烯-1,3-二醇。结果,已知的 (3aS*,4R*,7S*,7aS*)-3a,4,7,7a-四氢-4,7-甲桥-1H-茚-1-酮转化为 (1′S*,3′S*,3′aR*,4′S*,7′R*,7′aS*)-2′,3′,3′a,4′,7′,7′a-六氢-3′-羟基-4′、7′-甲桥-1′H-茚-1′-基苯甲酸酯,通过环氧酮的立体和区域选择性氢化物还原和顺序苯甲酰化,在脂肪酶存在下的酯交换条件下进行。苯甲酸酯和乙酸酯的氢化物还原反应产生了相应的手性二元醇,通过逆-Diels-Alder 反应,这些手性二元醇进一步转化为 C2-不对称 4-环戊烯-1,3-二醇的两种对映体。