New approaches towards the synthesis of the side-chain of mycolactones A and B

Org Biomol Chem. 2005 Jul 21;3(14):2524-33. doi: 10.1039/b505980a. Epub 2005 Jun 15.

Abstract

New approaches towards the synthesis of the C1'-C16' side-chain of mycolactones A and B from Mycobacterium ulcerans are reported. Chiral building block 4 (Fig. 2) with the correct stereochemistry was obtained starting from naturally occurring monosaccharides, i.e. D-glucose or L-rhamnose. The polyunsaturated moiety 3 was synthesized in only 3 steps from 2,4-dimethylfuran. The building blocks were connected through a Sonogashira coupling resulting in the fast and convergent assembly of an 8,9-dehydro analogue 2 of the side-chain of mycolactones A and B. The synthesis of 1 is at this stage hampered by the lack of a selective partial hydrogenation protocol for alkynes embedded in a conjugated system. Alternative strategies involving palladium catalyzed sp2-sp2 coupling between C7' and C8' or C9' and C10' (Fig. 1) were also explored.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Lactones / chemical synthesis*
  • Lactones / chemistry*
  • Macrolides
  • Molecular Structure
  • Stereoisomerism

Substances

  • Lactones
  • Macrolides
  • mycolactone A
  • mycolactone B