Total Synthesis of the Alkaloid (±)??Aspidophytine Based on Carbonyl Ylide Cycloaddition Chemistry

JM Mejía??Oneto, A Padwa

Index: Mejia-Oneto, Jose M.; Padwa, Albert Helvetica Chimica Acta, 2008 , vol. 91, # 2 p. 285 - 302

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Citation Number: 40

Abstract

Abstract The Rh II-catalyzed cycloaddition cascade of an indolyl-substituted α-diazo imide was used for the total synthesis of the complex pentacyclic alkaloid (±)-aspidophytine. Treatment of the resulting dipolar cycloadduct with BF 3⋅ OEt 2 induces a domino fragmentation cascade. The reaction proceeds by an initial cleavage of the oxabicyclic ring and formation of a transient N-acyl iminium ion which reacts further with the adjacent tert- ...