通过γ-羟基烯酮的氧杂-迈克尔/迈克尔环化反应实现功能化四氢呋喃的新型合成。

A novel synthesis of functionalized tetrahydrofurans by an Oxa-Michael/Michael cyclization of gamma-hydroxyenones.

作者信息

Greatrex Ben W, Kimber Marc C, Taylor Dennis K, Tiekink Edward R T

机构信息

Department of Chemistry, The University of Adelaide, South Australia 5004, Australia.

出版信息

J Org Chem. 2003 May 30;68(11):4239-46. doi: 10.1021/jo020700h.

DOI:10.1021/jo020700h

PMID:12762722

Abstract

An approach to highly functionalized tetrahydrofuran derivatives based upon a novel Oxa-Michael/Michael dimerization of cis-gamma-hydroxyenones is presented. The reaction begins with either 1,2-dioxines or trans-gamma-hydroxyenones and proceeds by addition of one molecule of trans-gamma-hydroxyenone to another molecule of cis- or trans-gamma-hydroxyenone catalyzed by an alkoxide or hydroxide base. Subsequent intramolecular Michael addition of the keto-enolate gives the observed tetrahydrofurans. Substitution at both the 2- and 4-positions of the gamma-hydroxyenone is tolerated; however, for 4-substituted gamma-hydroxyenones, selectivity issues arise due to the possibility of heterochiral or homochiral dimerizations. The major products were those with all contiguous groups trans.

摘要

本文介绍了一种基于顺式γ-羟基烯酮新型氧杂-迈克尔/迈克尔二聚反应制备高官能化四氢呋喃衍生物的方法。该反应以1,2-二氧六环或反式γ-羟基烯酮开始，通过醇盐或氢氧化物碱催化一分子反式γ-羟基烯酮加成到另一分子顺式或反式γ-羟基烯酮上进行。随后酮烯醇盐的分子内迈克尔加成得到观察到的四氢呋喃。γ-羟基烯酮的2-位和4-位均可进行取代；然而，对于4-取代的γ-羟基烯酮，由于异手性或同手性二聚的可能性，会出现选择性问题。主要产物是所有相邻基团均为反式的那些产物。