SEX-PHEROMONE OF PINE SAWFLIES - ENANTIOSELECTIVE LIPASE-CATALYZED TRANSESTERIFICATION OF ERYTHRO-3,7-DIMETHYLPENTADECAN-2-OL, DIPRIONOL

(2S,3S,7R/S)-3,7-Dimethylpentadecan-2-ol (2S,3S,7R/S)-1 was prepared w ith less then 0.5% of (2R,3R,7R/S)-3,7-dimethylpentadecan-2-ol via Pse udomonas sp. (PSL) catalysed transesterification of a 1:1:1:1 mixture of the four erythro-3,7-dimethylpentadecan-2-ols and vinyl acetate in n-heptane at initial low water activity (a(W) < 0.1). (2S,3S,7S)-3,7-D imethylpentadecan-2-ol (Diprionol) is the precursor to the behavioural ly active diprionyl acetate used by the female pine sawfly Neodiprion sertifer as a sexual pheromone. Several lipases, solvents and reaction conditions were tested, and the best results (enantiomeric ratio E = 110) were obtained with Pseudomonas sp. (PSL) and vinyl acetate in iso -octane at initial water activity a(W) < 0.32, When using Candida rugo sa (CRL, immobilised on polypropylene) as the catalyst in an esterific ation reaction with rac-4-methyl-dodecanoic acid and eicosanol at a(W) = 0.8 in cyclohexane a pronounced enantioselectivity was obtained (E = 19). Copyright (C) 1996 Elsevier Science Ltd