α-甲基-γ-羟基-α,β-不饱和酯的高立体选择性环氧化反应：原理及合成应用

Highly stereoselective epoxidation of alpha-methyl-gamma-hydroxy-alpha,beta-unsaturated esters: rationalization and synthetic applications.

作者信息

López Irakusne, Rodríguez Santiago, Izquierdo Javier, González Florenci V

机构信息

Departament de Química Inorgànica i Orgànica Universitat Jaume I, 12080 Castelló, Spain.

出版信息

J Org Chem. 2007 Aug 17;72(17):6614-7. doi: 10.1021/jo0709955. Epub 2007 Jul 26.

DOI:10.1021/jo0709955

PMID:17655257

Abstract

The diastereoselectivity of the nucleophilic epoxidation of gamma-hydroxy-alpha,beta-unsaturated esters having a methyl substituent at the alpha- or beta-position was investigated. Epoxidation of the alpha-methyl-substituted enoate was highly stereoselective, giving rise to the syn isomer. This finding was used to perform an enantioselective synthesis of a natural product having a beta-hydroxy-alpha-methylene-gamma-butyrolactone motif. The nucleophilic epoxidation of enoates was found to be irreversible. Models to explain the observed stereoselectivities are proposed.

摘要

研究了在α-或β-位具有甲基取代基的γ-羟基-α,β-不饱和酯的亲核环氧化反应的非对映选择性。α-甲基取代的烯酸酯的环氧化反应具有高度的立体选择性，生成顺式异构体。这一发现被用于对具有β-羟基-α-亚甲基-γ-丁内酯基序的天然产物进行对映选择性合成。发现烯酸酯的亲核环氧化反应是不可逆的。并提出了解释观察到的立体选择性的模型。