Asymmetric synthesis of trans-4,5-dioxygenated cyclopentenone derivatives by organocatalyzed rearrangement of pyranones and enzymatic dynamic kinetic resolution
作者:João P.M. Nunes、Luís F. Veiros、Pedro D. Vaz、Carlos A.M. Afonso、Stephen Caddick
DOI:10.1016/j.tet.2011.02.018
日期:2011.4
Dioxygenated cyclopentenones are versatile building blocks for the synthesis of several natural products. Herein we report a direct asymmetric synthesis of trans-4,5-dioxygenated cyclopentenone derivatives through base-catalyzed rearrangement of pyranones followed by dynamic kinetic resolution. Milder conditions than previously reported for this rearrangement have been found regarding amine base catalysis
双氧合环戊烯酮是用于合成多种天然产物的通用构建基块。在本文中,我们报告了通过碱催化的吡喃酮重排,然后进行动态动力学拆分,直接反对称合成反式-4,5-二加氧环戊烯酮衍生物。在胺碱催化,溶剂和温度影响方面,已经发现比先前报道的用于这种重排的条件更温和的条件。所有数据都支持一种机制,该机制涉及由吡喃酮衍生的烯醇的电环开环形成的中间体的环化。我们已经开发了反式-4-叔丁基不对称合成的条件经由脂肪酶诱导的动力学动力学拆分,以81%的收率和95%的ee得到-丁氧基-5-羟基环戊-2-烯酮和类似的双加氧环戊烯酮。