2, 2'-Dicarbomethoxy-9, 9'-bitriptycyl. Synthesis, conformational stability, and separation and identification of the conformers

LH Schwartz, C Koukotas, P Kukkola…

Index: Schwartz, Leonard H.; Koukotas, Constantine; Kukkola, Paivi; Yu, Chen Shek Journal of Organic Chemistry, 1986 , vol. 51, # 7 p. 995 - 999

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Citation Number: 17

Abstract

5b, X= CH, 2, 3, and 4, both sets of interfering substituents in 9, 9'-bitriptycyls are directed toward each other. In addition, the interfering groups are small hydrogen atoms. This minimizes ground-state strain. The combination of a high rotational transition state energy with an uncongested ground state is most favorable for a large rotational barrier. 2b As anticipated, 2, 2'-dimethyl-9, 9'-bitriptycyl (5b) was found to have an enormous rotational ...