An Enantioselective Total Synthesis of (+)-Duocarmycin SA

J Org Chem. 2018 Apr 6;83(7):3928-3940. doi: 10.1021/acs.joc.8b00285. Epub 2018 Mar 26.

Abstract

An efficient, concise enantioselective total synthesis of the potent antitumor antibiotic (+)-duocarmycin SA is described. The invented route is based on a disconnection strategy that was devised to facilitate rapid and efficient synthesis of key core compounds to enable preclinical structure-activity relationship investigations. The key tricycle core was constructed with a highly enantioselective indole hydrogenation to set the stereocenter and a subsequent hitherto unexplored vicarious, nucleophilic-substitution/cyclization sequence to effectively forge a final indole ring. Additionally, the development of a stable sulfonamide protecting group capable of mild chemoselective cleavage greatly enhanced sequence yield and throughput. An understanding of key reaction parameters ensured a robust, reproducible sequence easily executable on decagram scales to this highly promising class of compounds.

MeSH terms

  • Cyclization
  • Duocarmycins
  • Hydrogenation
  • Indoles / chemical synthesis*
  • Indoles / chemistry*
  • Molecular Structure
  • Pyrroles / chemical synthesis
  • Pyrroles / chemistry
  • Stereoisomerism

Substances

  • Duocarmycins
  • Indoles
  • Pyrroles
  • duocarmycin SA
  • indole