Enzymatic resolution of albicanol and its application to the synthesis of (−)-copalic acid

Stereoselective Synthesis of Terpenoids through Lipase-Mediated Resolution Approaches

“…Other enzymes were screened [26], and only the combined use of lipase from Candida antartica and vinyl propionate allowed the resolution of this isomer, although with modest enantioselectivity (E = 6.7). Similarly, the resolution of the sesquiterpenes drimenol (15) and albicanol (16), by means of this enzymatic approach, was extensively studied [27][28][29][30]. Moreover, in these cases, to achieve suitable enantioselectivity, specific acylation conditions were identified.…”

Enzyme-Mediated Synthesis of Sesquiterpenes

“…Both enantiomeric forms of 27 have been used as chiral building blocks in natural products synthesis. Racemic albicanol of synthetic origin was resolved [64] through enzyme-mediated irreversible acetylation using lipase QL as catalyst and isopropenyl acetate as acyl donor to afford the (8aR)-isomer in very good enantiomeric purity.…”

Recent Advances in the Syntheses of Decalin Type Natural Products

“…20,21 The reaction of 60 and dimethyl carbonate in the presence of NaH gave the -keto ester (61), which was subjected to biomimetic cyclization to afford the (±)-cyclic-keto ester (62) in 42% overall yield from 60. Wittig olefination of (±)-62 followed by reduction gave (±)-64 in 90% overall yield from (±)-62.…”

“…20 This enzymatic esterification was improved by exchange of acylating reagent. 21 Enzymatic esterification of (±)-64 in the presence of vinyl myristate and lipase "QL" gave (8aR)-64 (>99% ee, 43% yield) and the myristate (8aS)-69 (82% ee, 53% yield). The 82% ee of (8aS)-69 was hydrolyzed followed by repeated acylation to afford the optically pure (8aS)-69 in 74% overall yield.…”