Total syntheses of (-)-Curvularin and Xestodecalactone A, formal total syntheses of (-)-Citreofuran, (+)-12-oxo-curvularin, (+)-Sporostatin, synthetic efforts toward (-)-Caylobolide A.

摘要

This dissertation demonstrates total syntheses of Xestodecalactone A and Curvularin. Formal total syntheses of Sporostatin, 12-oxo-curvularin and Citreofuran are also described. The key reaction utilized in the construction of these fused resorcinylic macrolides, is Pd-catalyzed &agr;-arylation of a &agr;-bromo ester and boronic acid. The first chapter gives a brief introduction of natural products and its importance. Special attention was given to 1,5-diols. Different ways to prepare 1,5-diols and current methods available to determine the absolute and absolute stereochemistry of 1,5-diols were discussed in details. The second chapter highlights the underutilized Pd-catalyzed &agr;-arylation reaction and its potential in the synthesis of resorcinylic macrolides. Critical analyses of various previous methods of &agr;-arylation reactions were included. The third chapter recounts the total synthesis of (+)-xestodecalactone A and formal total synthesis of (+)-sporostatin. The fourth chapter illustrates the total synthesis of (-)-curvularin. It also includes its various biological activities and all the previous approaches. The fifth chapter explains formal syntheses of (-)-12-oxo-curvularin and (-)-citreofuran. The final chapter is dedicated to the synthetic effort toward (-)-caylobolide A, a unique 36 member macrolactone containing a contiguous pentand of 1,5-diol. Successful synthesis of two diastereomeric C25-C40 subunits and a potential 1,5-syn-polyol fragment were delineated.