Ring expansion of cyclobutanones to cyclopentanones via. alpha.-lithioalkyl aryl sulfoxides and selenoxides

RC Gadwood, IM Mallick…

Index: Gadwood, Robert C.; Mallick, Ishwar M.; DeWinter, Amy J. Journal of Organic Chemistry, 1987 , vol. 52, # 5 p. 774 - 782

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Citation Number: 33

Abstract

Reaction of a-lithioalkyl 2-chlorophenyl sulfoxides (prepared from the corresponding sulfoxides and LDA) with cyclobutanones affords adducts which undergo ring expansion to cyclopentanones upon treatment with potassium hydride. This reaction only works for cyclobutanones substituted at C2 with at least one phenyl or alkenyl group (type I and type I1 cyclobutanones). Cyclobutanones substituted at C2 with at least one alkyl group (type ...