Asymmetric Assembly of Steroidal Tetracyclic Skeletons

Abstract

Steroids have long played a vital role in the organic synthesis because of their unique structural design and associated biological properties. In recent years, asymmetric synthesis has emerged as a powerful tool for assembling the tetracyclic framework with high level of molecular diversity. This review summarizes the latest developments in the enantioselective syntheses of both natural and synthetic steroids incorporationg the carbocyclic skeleton. The approaches to the synthesis of steroids and related molecules are based primarily on the use of chiral starting materials, the employment of reagent-controlled asymmetric induction assisted by chiral complexes, chiral Lewis acids or organocatalysts, or the utilisation of chiral auxiliaries.