STEREOSELECTIVE RADICAL ADDITIONS OF GAMMA-OXY-ALPHA,BETA-UNSATURATED ESTER DERIVATIVES - 1,2-ASYMMETRIC INDUCTION IN ACYCLIC AND CYCLIZATION SYSTEMS

被引:18
作者
MORIKAWA, T
WASHIO, Y
HARADA, S
HANAI, R
KAYASHITA, T
NEMOTO, H
SHIRO, M
TAGUCHI, T
机构
[1] TOKYO COLL PHARM,HACHIOJI 19203,TOKYO,JAPAN
[2] RIGAKU CORP,AKISHIMA,TOKYO 196,JAPAN
来源
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1 | 1995年 / 03期
关键词
D O I
10.1039/p19950000271
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
Examination was made of 1,2-asymmetric induction in the addition of alkyl radicals to gamma-oxy-alpha,beta-unsaturated ester derivatives 1 and 2 prepared from ethyl lactate and (R)-2,3-0-isopropylideneglyceraldehyde 3, respectively. The addition reactions of hexyl, cyclohexyl and 3-phenylpropyl radicals to (Z)-2 derived from aldehyde 3 gave beta-addition products with syn-stereoselectivity (syn:anti = 8.6:1-syn only). The reactions of (E)-2 were non-stereoselective. Based on allylic strain, a transition-state model for the syn-stereoselectivity is proposed. 1,2-Asymmetric induction was carried out in radical cyclisation to synthesize optically active cyclohexane derivatives.
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页码:271 / 281
页数:11
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