Cyclopentenone synthesis from 1, 1-dichloroallyllithium-ketone adducts as well as from dichlorocarbene-allyl alcohol adducts.

T Hiyama, M Shinoda, M Tsukanaka…

Index: Hiyama, Tamejiro; Shinoda, Masaki; Tsukanaka, Masao; Nozaki, Hitosi Bulletin of the Chemical Society of Japan, 1980 , vol. 53, # 4 p. 1010 - 1014

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Citation Number: 18

Abstract

Treatment of (3, 3-dialkyl-2, 2-dichlorocyclopropyl) methanols with hydrobromic acid gives 2- cyclopentenones through postulated intermediates, 3-chlorocyclopentadienyl cations. Another method which should give the same cationic intermediates involves trifluoroacetic acid catalyzed reaction of 3, 3-dichloro-1-alken-4-ols. This is found to be particularly useful for cyclopentenone annulation.