Stereoselective synthesis of 1,2-diols by the cycloadditive strategy: total synthesis of (±)-exo-brevicomin and (±)-and (–)-pestalotin
Abstract
Highly selective reductions of 5-acyl-2-isoxazolines and conversion of the resulting syn-5-hydroxyalkyl-2-isoxazolines into syn-diols are key steps in concise syntheses of (±)-exo-brevicomin, and (±)-pestalotin. With an asymmetric nitrile oxide as starting material, cycloaddition with the acrylate derivative of Oppolzer's camphor sultam leads to a synthesis of (–)-pestalotin.