HIGH DIASTEREOSELECTIVITY IN THE CYCLIZATION OF 1,5-BIRADICALS - WHAT CAUSES SUCH SIZABLE STERIC BARRIERS TO BIRADICAL COUPLING

被引：16

作者：

WAGNER, PJ

PARK, BS

机构：

[1] Chemistry Department, Michigan State University, East Lansing

来源：

TETRAHEDRON LETTERS | 1991年 / 32卷 / 02期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/0040-4039(91)80844-V

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The high diastereoselectivities observed in the photocyclization of alpha-(o-ethylphenyl)acetophenones appear to reflect conformational equilibria in the triplet 1,5-biradical intermediates rather than steric barriers created during cyclization. The necessary biradical triplet-->singlet intersystem crossing is proposed to occur along the cyclization reaction coordinate since the orthogonality of the two singly-occupied p orbitals does not depress biradical lifetimes.

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页码：165 / 168

页数：4

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