Stereochemistry of the cyclization-rearrangement of (+)-copalyl diphosphate to (-)-abietadiene catalyzed by recombinant abietadiene synthase from Abies grandis

Org Lett. 2000 Mar 9;2(5):573-6. doi: 10.1021/ol991230p.

Abstract

[reaction: see text] Syntheses and enzymatic cyclizations of 8alpha-hydroxy-17-nor copalyl diphosphate (8a), (15R)-[15-2H1] 8b, and (15R,17E)-[15-3H1,17-2H1] copalyl diphosphate ([2H,3H] 2) catalyzed by recombinant abietadiene synthase (rAS) gave 17-nor manoyl oxide (9a), (16E)-[16-2H1] 9b, and (15S,16R)-[16-2H1,16-3H1] abietadiene ([2H1,3H1] 4), respectively. These and other results indicate that conversion of CPP (2) to abietadiene (4) occurs by anti S(N)' cyclization to a sandaracopimar-15-en-8-yl carbocation intermediate (13+, 13beta-methyl) followed by hydrogen transfer and methyl migration suprafacially on the si face of the vinyl group.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Abietanes*
  • Catalysis
  • Isomerases / chemistry*
  • Organophosphates / chemistry*
  • Phenanthrenes / chemistry*
  • Recombinant Proteins / chemistry
  • Stereoisomerism
  • Trees / enzymology*

Substances

  • Abietanes
  • Organophosphates
  • Phenanthrenes
  • Recombinant Proteins
  • abieta-7(8),13(14)-diene
  • copalyl diphosphate
  • Isomerases
  • abietadiene cyclase