ON THE MECHANISM OF WITTIG REACTIONS WITH CYCLIC ANHYDRIDES .2.

被引:12
作者
KAYSER, MM [1 ]
HATT, KL [1 ]
YU, HS [1 ]
HOOPER, DL [1 ]
机构
[1] DALHOUSIE UNIV, DEPT CHEM, HALIFAX B3H 4J3, NS, CANADA
来源
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE | 1993年 / 71卷 / 07期
关键词
D O I
10.1139/v93-135
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
A study by NMR spectroscopic methods and trapping experiments of the mechanism of Wittig reactions between stabilized phosphoranes and unsymmetrically substituted cyclic anhydrides suggests that two reactions are involved: (1) a low-energy, reversible formation of acyclic adducts; and (2) a higher energy ''Wittig olefination'' reaction leading to enol-lactones The latter, more selective, transformation requires a more highly organized transition state in which pi-stacking and stabilizing complexations are important factors.
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页码:1010 / 1021
页数:12
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