Organocatalytic Double Michael Reaction of 7-Oxohept-2-enoates and Nitrostyrene – Formal Synthesis of (–)-α- and (–)-β-Lycorane
作者:Bor-Cherng Hong、Roshan Y. Nimje、Ming-Fun Wu、Amit A. Sadani
DOI:10.1002/ejoc.200701122
日期:2008.3
Organocatalytic conjugate addition of 7-oxohept-2-enoate to nitrostyrene provided an ω-nitro-α,β-unsaturated ester. Subsequent intramolecular cyclization afforded the highly functionalized cyclohexane carboester with four stereogenic centers with high diastereoselectivity and high enantioselectivity (>99 % ee). Some adducts were transformed into the intermediates of the synthesis of (–)-α- and (–)-β-lycorane
7-oxohept-2-enoate 与硝基苯乙烯的有机催化共轭加成提供了 ω-硝基-α,β-不饱和酯。随后的分子内环化提供了具有四个立体中心的高度官能化的环己烷碳酸酯,具有高非对映选择性和高对映选择性(> 99 % ee)。一些加合物转化为合成 (-)-α- 和 (-)-β-lycorane 的中间体。将反应应用于相应的二醛提供双环 [2.2.2] 辛烷。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)