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Updated: Jun 19, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
A one-pot, base-free annelation approach to alpha-alkylidene-gamma-butyrolactones
Russell R A Kitson1, Richard J K Taylor, John L Wood
1Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
Abstract:
A novel annelation procedure has been developed for the conversion of gamma-hydoxy enones into alpha-alkylidene-gamma-butyrolactones. This one-pot method utilizes the Bestmann ylide (triphenylphosphoranylideneketene) and proceeds by way of acylation followed by an intramolecular conjugate addition/proton transfer/Wittig olefination sequence. The procedure is "base-free" and is useful for the preparation of a range of alpha-alkylidene-gamma-butyrolactones including alpha-methylene-gamma-butyrolactone examples, which can be particularly base-sensitive.
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