Stereoselective Syntheses of Epothilones A and B via Nitrile Oxide Cycloadditions and Related Studies
作者:Jeffrey W. Bode、Erick M. Carreira
DOI:10.1021/jo015791h
日期:2001.9.1
epothilones A and B are described. The routes described make extensive study of nitrileoxide cycloadditions as surrogates for aldoladdition reactions and have led to the realization of a highly convergent synthesis based on the Kanemasa hydroxyl-directed nitrileoxide cycloaddition. As well, our synthetic efforts have led to the development of new reaction methodologies and served as the proving ground for
A Modular Approach to Polyketide Building Blocks: Cycloadditions of Nitrile Oxides and Homoallylic Alcohols
作者:Nina Lohse-Fraefel、Erick M. Carreira
DOI:10.1021/ol0504953
日期:2005.5.1
A general approach to the diastereoselective synthesis of Delta(2)-isoxazolines via magnesium-mediated, hydroxyl-directed diastereoselective nitrile oxide cycloadditions of homoallylic alcohols and monoprotected homoallylic diols is disclosed. A broad spectrum of aliphatic and aromatic nitrile oxides and a variety of homoallylic alcohols participate in the cycloaddition, thus expanding the scope of
starting materials suffice for the modular synthesis of all possible polypropionate diastereomers. This general method for the diastereoselective synthesis of syn, anti, and methyl ketone aldol adducts utilizes a powerful MgII -mediated, hydroxy-directed nitrile oxide cycloaddition. The free hydroxy group provides an ideal synthetic handle enabling the rapid assembly of complex polyketide structures