Diastereoselective syn or anti opening of propargylic epoxides. Synthesis of α-allenic alcohols
作者:A. Alexakis、I. Marek、P. Mangeney、J.F. Normant
DOI:10.1016/s0040-4020(01)96911-x
日期:1991.1
Propargylic epoxides easily react with Grignard reagents and catalytic amounts of copper(I) salt to afford α-allenic alcohols. The reaction is highly diastereoselective and its stereochemical outcome ( or isomer) can be fully controlled. The diastereomer, probably arising through an addition-elimination mechanism, is better obtained with RMgCl and copper(I) bromide, whereas the diastereomer, is better
炔丙基环氧化物容易与格氏试剂和催化量的铜(I)盐反应生成α-烯丙醇。该反应是高度非对映选择性的,其立体化学结果(或异构体)可以得到完全控制。使用RMgCl和溴化铜(I)可以更好地获得可能是通过加成消除机理产生的非对映异构体,而使用RMgBr和络合的铜(I)盐可以更好地获得非对映异构体。苯乙炔基环己烯氧化物与RLi和催化量的铜盐通过还原性锂离子反应,提供立体选择性的烯丙基锂试剂。