Synthesis of terpenes containing the bicyclo [3.1. 1] heptane ring system by the intramolecular [2+ 2] cycloaddition reaction of vinylketenes with alkenes. Preparation of …

YS Kulkarni, M Niwa, E Ron…

Index: Kulkarni, Yashwant S.; Niwa, Maho; Ron, Eyal; Snider, Barry B. Journal of Organic Chemistry, 1987 , vol. 52, # 8 p. 1568 - 1576

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Citation Number: 41

Abstract

Isomerization over Pd gave chrysanthenone (6) in quantitative yield. Wolff-Kishner reduction gave@-pinene (5) in 70% yield. A similar sequence of reactions starting from (.%', E)-and (E, E)-farnesoyl chloride gave ketones 51 and 57, which were converted to@-cis-bergamotene (8) and@-trans-bergamotene (9), respectively.@-Copaene (10) and@-ylangene (11) were prepared from 57 by a three-step sequence. Treatment of the imidazolide 59 with tri-n- ...