A new method of preparation of opticallyactive α-hydroxy ketone derivatives has been developed. Incubation of (Z)-3-propionyloxy-4-benzyloxy-2-pentene (1a) with lipase OF gave optically pure (R)-enol propionate 1a, which in turn was convened without racemization to (R)-ketone 2a by the aid of LiAlH4.
The dynamic resolution of racemic acyclic α-hydroxy ketone derivatives is accomplished using an optically active host compound, TADDOL, under basic conditions to give the corresponding optically active ketones.
new method for the preparation of optically active acyclic α-hydroxy ketone derivatives by thermodynamic resolution using a chiral host compound is described. We examined the resolution of racemic 2-benzyloxy-3-pentanone with chiral host compounds in various solvents. After optimization of the reaction conditions, it has become apparent that the opticalresolution could occur only under certain strict
描述了一种使用手性主体化合物通过热力学拆分制备光学活性无环 α-羟基酮衍生物的新方法。我们研究了外消旋 2-benzyloxy-3-pentanone 与手性主体化合物在各种溶剂中的拆分。在优化反应条件后,很明显,光学拆分只能在溶剂、主体化合物和底物浓度的某些严格条件下发生。在室温下在 MeOH-H 2 O (1:1) 中搅拌带有环己基环的 (-)-TADDOL 的酮悬浮液,该悬浮液源自 L-酒石酸乙酯,产生具有高对映选择性的包合物,得到 (S) - 含高达 99% ee 的酮。另一方面,从滤液中得到的(R)-酮的ee可以通过使用(+)-TADDOL的相同程序得到改善;最后,得到几乎光学纯形式的酮的两种对映异构体。通过 ESI-TOFMS 分析形成的复合体假设主客比为 1:1。这种拆分过程也适用于其他基材,以提供相应的光学活性酮。