Synthesis, Chemical Properties, and Structure of a Sterically Hindered Ketone, 2, 2, 5, 5-Tetramethyl-4, 4-diphenyl-3-thiolanone.

J Nakayama, A Hirashima, Y Yokomori

Index: Nakayama, Juzo; Hirashima, Atsushi; Yokomori, Yoshinobu Bulletin of the Chemical Society of Japan, 1991 , vol. 64, # 12 p. 3593 - 3599

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Citation Number: 2

Abstract

A sterically hindered ketone, 2, 2, 5, 5-tetramethyl-4, 4-diphenyl-3-thiolanone (1), was synthesized in two steps starting from 2, 2, 4, 4-tetramethyl-1, 5-diphenyl-3-thiapentane-1, 5- dione. The carbonyl group of 1 is unreactive toward a series of nucleophiles which are bulkier than hydride or its equivalents. The observed unreactivity is ascribed to the steric hindrance enhanced by the two methyl groups on C-5 (“buttressing” effect). The result of ...