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Updated: Aug 28, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Total Synthesis of Schisanlactone A and Ganodermalactone H via Selective Transformation of a Cycloheptatriene
Soichiro Suzuki1, Hidetaka Kuroiwa1, Ei-Ichi N Kodama2
1Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
Abstract:
Herein we report the first total synthesis of schisanlactone A (1) and ganodermalactone H (2). The synthetic strategy features a domino [4 + 3] cycloaddition to construct a 7/6/5-membered ring system. This is followed by selective double-bond isomerization and then reduction of one of the three double bonds on the unsaturated seven-membered ring. Regio- and stereoselective reduction using SmI2 was key to construction of the challenging cycloheptadiene moiety. This approach provides a versatile foundation for the total synthesis of various seco-lanostane-type triterpenoids.
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