Asymmetric, stereocontrolled total synthesis of (+) and (−)-spirotryprostatin B via a diastereoselective azomethine ylide [1, 3]-dipolar cycloaddition reaction

PR Sebahar, H Osada, T Usui, RM Williams

Index: Sebahar, Paul R; Osada, Hiroyuki; Usui, Takeo; Williams, Robert M Tetrahedron, 2002 , vol. 58, # 32 p. 6311 - 6322

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Citation Number: 94

Abstract

The asymmetric, stereocontrolled total syntheses of (+) and (−)-spirotryprostatin B (2) are described. Formation of the core pyrrolidine ring was accomplished via a diastereoselective asymmetric [1, 3]-dipolar cycloaddition reaction. Addition of 3-methoxy-3-methylbutanal to (5R, 6S)-2, 3, 5, 6-tetrahydro-5, 6-diphenyl-1, 4-oxazin-2-one generated an azomethine ylide that reacted with ethyl oxindolylidene acetate to furnish the desired cycloadduct (11) ...