Jheengut Vishal, Ward Dale E
Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon SK S7N 5C9, Canada.
J Org Chem. 2007 Sep 28;72(20):7805-8. doi: 10.1021/jo701546f. Epub 2007 Sep 7.
(6S,7S,8S,9R,10S)-(--)-Membrenone B was synthesized in nine steps (9.4% overall yield) beginning with two-directional aldol coupling of tetrahydro-4H-thiopyran-4-one with racemic 1,4-dioxa-8-thiaspiro[4.5]decane-6-carboxaldehyde. The first aldol reaction occurs with dynamic kinetic resolution to give a single adduct (>98% ee). The second aldol reaction is highly diastereoselective (three of eight possible adducts), and both major products are converted to membrenone B. The route also constitutes a formal synthesis of membrenone A.
以四氢-4H-硫代吡喃-4-酮与外消旋1,4-二氧杂-8-硫杂螺[4.5]癸烷-6-甲醛进行双向羟醛缩合反应为起始，经九步反应合成了(6S,7S,8S,9R,10S)-(-)-膜醌B（总产率9.4%）。第一步羟醛反应通过动态动力学拆分得到单一加合物（对映体过量>98%）。第二步羟醛反应具有高度非对映选择性（八种可能的加合物中的三种），且两种主要产物均转化为膜醌B。该路线也构成了膜醌A的形式合成。
