Title

Diosphenol-based approach to the a-ring functionalization of advanced Taxol precursors.

Document Type

Article

Publication Date

9-2006

Abstract

Several different approaches to the A-ring functionalization of an advanced, highly functionalized diosphenol precursor to Taxol are described. The first phase of the undertaking consists of an assessment of those reagents conducive to reaction at the enolic oxygen (silylation, methylation, allylation, and acylation). Transformations involving an alternative attack at the enol carbon center (bromination, selenation) have also been defined. Sodium borohydride reduction operates from the beta-face of C-14 as long as the C-1 hydroxyl is not protected so as to offer steric exclusion. Complications associated with various aspects of these methodological undertakings are addressed. The most advanced oxygenation achievements were realized by way of a noteworthy sequence involving epoxidation of the O-methyl ether, methanolysis under mildly acidic conditions, and regioselective oxidation of diol 38 to give 39.

Journal

Journal of Organic Chemistry

Volume

71

Issue

19

First Page

7329

Last Page

7336