38237-44-4Relevant academic research and scientific papers
Stereochemistry of the cyclization-rearrangement of (+)-copalyl diphosphate to (-)-abietadiene catalyzed by recombinant abietadiene synthase from Abies grandis
Ravn, Matthew M.,Coates, Robert M.,Flory, Janice E.,Peters, Reuben J.,Croteau, Rodney
, p. 573 - 576 (2000)
(equation presented) Syntheses and enzymatic cyclizations of 8α,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 SN′ cyclization to a sandaracopimar-15-en-8-yl carbocation intermediate (13+, 13β-methyl)' followed by hydrogen transfer and methyl migration suprafacially on the si face of the vinyl group.
SYNTHESIS OF LABDA-8(17),13(14)-DIENE-15,16-OLIDE AND 15,16-EPOXY-LABDA-8(17),13(16)-14-TRIENE AND THEIR REARRANGEMENT TO CLERODANE DERIVATIVES
Nakano, Tatsuhiko,Martin, Alfonso,Rojas, Anibal
, p. 1217 - 1219 (2007/10/02)
The title compounds 1b and 1c were synthesized from manool.On treatment with either trifluoroacetic acid or formic acid 1b provided in nearly 100percent yield 4a with a rearranged labdane skeleton.With sulfuric acid, however, 1b gave solely Δ8,9-isomer 5.Reduction of 4a with lithium diisobutylaluminium hydride afforded 4b.On treatment with sulfuric acid 4a reverted to 5.Rearrangement of the epoxide 6 with boron trifluoride-etherate led to a complex product mixture from wich no pure substance was obtained.
