THERMAL RACEMIZATION OF METHYL-SUBSTITUTED HEXAHELICENES

被引：43

作者：

BORKENT, JH ^{[1
]}

LAARHOVEN, WH ^{[1
]}

机构：

[1] CATHOLIC UNIV TOERNOOIVELD,DEPT ORGAN CHEM,NIJMEGEN,NETHERLANDS

来源：

TETRAHEDRON | 1978年 / 34卷 / 16期

关键词：

D O I：

10.1016/0040-4020(78)88387-2

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Rates of racemization of several Me-substituted hexahelicenes have been measured. It appeared that Me groups at the positions 3, 4, 13 and 14 have no influence; at the positions 2 and 15 the effect is small; Me-substitution at C(1) and C(16) leads, however, to a large increase of the free energy of activation. From an analysis of the data the suggestion is made that the conformation of highest energy during racemisation of 1-methyl- and 1,16-dimethylhexahelicene (and possibly also of hepta and octahelicene) is that with the terminal rings in orthogonal position. © 1978.

引用

页码：2565 / 2567

页数：3

共 5 条

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