N-Acyliminium ion rearrangements: generalities and application to the synthesis of pyrrolizidine alkaloids

DJ Hart, TK Yang

Index: Hart, David J.; Yang, Teng-Kuei Journal of Organic Chemistry, 1985 , vol. 50, # 2 p. 235 - 242

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Citation Number: 72

Abstract

N-Acyliminium ions of the 2-aza-1, 5-hexadienyl type frequently rearrange to isomeric ions by a process which is formally a 2-ma-Cope rearrangement. When gem-dimethyl substitution is present at C-4 of the initially formed N-acyliminium ion, the rearranged ion cyclizes to afford a substituted pyrrolidine. This rearrangement-cyclization can be used to prepare pyrrolizidinones and indolizidinones and has been applied to enantioselective ...