Organocatalytic Enantioselective Michael鈥揗ichael鈥揗ichael鈥揂ldol Condensation Reactions: Control of Five Stereocenters in a Quadruple-Cascade Asymmetric Synthesis of Highly Functionalized Hexahydrophena

详细信息    查看全文

• 作者：Arun Raja ; Bor-Cherng Hong ; Gene-Hsiang Lee
• 刊名：Organic Letters
• 出版年：2014
• 出版时间：November 7, 2014
• 年：2014
• 卷：16
• 期：21
• 页码：5756-5759
• 全文大小：306K
• ISSN：1523-7052

文摘

A cascade organocatalysis has been developed for the enantioselective synthesis of a highly functionalized hexahydrophenanthrene-2-carbaldehyde containing five contiguous stereogenic centers with high diastereoselectivity and high enantioselectivity (>99% ee). The one-pot method comprises a cascade of organocatalytic Michael鈥揗ichael鈥揗ichael鈥揳ldol reactions of 2-methyl-1,5-dinitro-3-((E)-2-nitrovinyl)benzene and 伪,尾-unsaturated aldehydes (e.g., cinnamaldehyde). The structure and absolute configuration of a product were confirmed by X-ray analysis of an appropriate derivative.