Synthesis of 7-deoxypancratistatin from carbohydrates by the use of olefin metathesis

Chemistry. 2006 Apr 12;12(12):3243-53. doi: 10.1002/chem.200501429.

Abstract

The stereocontrolled synthesis of (+)-7-deoxypancratistatin is described. The convergent synthesis has been achieved by two different strategies, both of which commence from a pentose and piperonal. The latter is converted into allylic bromide 7, which is then coupled with a protected methyl 5-deoxy-5-iodo-D-ribofuranoside in the presence of zinc metal. The first strategy involves a total of only 13 steps from D-ribose and piperonal, but suffers from a low yield in the zinc-mediated reaction between ribofuranoside 9, benzylamine, and bromide 7. The second strategy involves a total of 18 steps from D-xylose and piperonal. The former is converted into ribofuranoside 28, which is coupled with bromide 7 in the presence of zinc, and this is followed by ring-closing olefin metathesis. Subsequent Overman rearrangement, dihydroxylation, and deprotection then affords the natural product.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Amaryllidaceae Alkaloids / chemical synthesis*
  • Amaryllidaceae Alkaloids / chemistry
  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / chemistry
  • Carbohydrates / chemistry*
  • Isoquinolines / chemical synthesis*
  • Isoquinolines / chemistry

Substances

  • 7-deoxypancratistatin
  • Alkenes
  • Amaryllidaceae Alkaloids
  • Antineoplastic Agents
  • Carbohydrates
  • Isoquinolines