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