Formation of the steroidal C-25 chiral center via the asymmetric alkylation methodology

Org Biomol Chem. 2015 Jan 21;13(3):776-82. doi: 10.1039/c4ob02123a.

Abstract

A novel approach for the preparation of steroids containing a chiral center at C-25 is reported. The key stereochemistry inducing step was asymmetric alkylation of pseudoephenamine amides of steroidal C-26 acids. The reaction proceeded with high diastereoselectivity (dr > 99 : 1). The developed methodology was successfully applied to the synthesis of (25R)- and (25S)-cholestenoic acids as well as (25R)- and (25S)-26-hydroxy brassinolides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Amides
  • Amphetamines / chemistry*
  • Brassinosteroids / chemical synthesis*
  • Cholestenes / chemical synthesis*
  • Molecular Structure
  • Stereoisomerism

Substances

  • Amides
  • Amphetamines
  • Brassinosteroids
  • Cholestenes
  • cholestenoic acid
  • pseudoephenamine