A stereodivergent synthesis of β-hydroxy-α-methylene lactones via vinyl epoxides

被引:19
作者
Davoust, Marion [1 ]
Cantagrel, Frederic [1 ]
Metzner, Patrick [1 ]
Briere, Jean-Francois [1 ,2 ,3 ]
机构
[1] Univ Caen, Lab Chim Mol & Thioorgan, ENSICAEN, CNRS, F-14050 Caen, France
[2] IRCOF, INSA Rouen, F-76131 Mont St Aignan, France
[3] Univ Rouen, CNRS, UMR 6014, COBRA, F-76131 Mont St Aignan, France
关键词
D O I
10.1039/b802310g
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
A catalytic diastereoselective sulfonium ylide epoxidation of aldehydes furnished original vinyl epoxides, having an MBH backbone. These highly functionalised building blocks were used for a formal synthesis of the antibiotic conocandin, and opened up a stereodivergent route towards beta-hydroxy-alpha-methylene lactones, core units of naturally occurring compounds. Under acidic conditions, the oxiranes were mainly transformed, with moderate to good yields, into trans beta-hydroxy-alpha-methylene lactones. On the other hand, a user-friendly palladium-catalysed CO2 insertion and cyclisation sequence gave the cis beta-hydroxy-alpha-methylene lactone counterparts along with an interesting cis-trans equilibration of the pi-allyl intermediates.
引用
收藏
页码:1981 / 1993
页数:13
相关论文
共 101 条