Syntheses of (-)-Tripterifordin and (-)-Neotripterifordin from Stevioside

  • J Org Chem. 2018 Feb 2;83(3):1606-1613. doi: 10.1021/acs.joc.7b02916.
Shoji Kobayashi  1 ,  Keisuke Shibukawa  1 ,  Yoshiki Hamada  1 ,  Takuma Kuruma  1 ,  Asako Kawabata  1 ,  Araki Masuyama  1
Affiliations
  • 1. Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology , 5-16-1 Ohmiya, Asahi-ku, Osaka 535-8585, Japan.
PMID: 29328659 DOI: 10.1021/acs.joc.7b02916
Abstract

We report short syntheses of (-)-tripterifordin and (-)-neotripterifordin, potent inhibitors of HIV replication, from stevioside, a natural sweetener used worldwide. The key transformations are reduction at C13 through the formation of a tertiary chloride and subsequent three-step lactonization including a selective iodination at C20 by the photoreaction of the C19-alcohol. The title compounds were reliably obtained from stevioside in 9 and 11 steps (with 5-7 isolation steps), respectively. Additionally, the related lactone-containing ent-kaurenes, doianoterpenes A and B, and two more natural products were synthesized.

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