ENZYMATIC AND CHROMATOGRAPHIC RESOLUTION OF ALCOHOLIC PRECURSORS IN THE SYNTHESIS OF MUSCARINE

The racemates of the title alcohols with acetylenic (rac-2, rac-3) and , with some limitation, allenic skeletons (rac-4) are useful substrate s for enzymatic resolution by acylation or deacylation, with a subsequ ent enantioconvergent step by inversion of the undesirable enantiomer. Of all the tested-hydrolases, a lipase from Pseudomonas cepacia (PSL) has been proven as especially suitable. The PSL-mediated acylations o f rac-2-3 by vinyl acetate proceed with a high enantioselectivity. By immobilization on celite, the rate of acylation is drastically increas ed. The protective group of the primary hydroxylic group has no influe nce either on the enzyme activity or enantioselectivity of the kinetic resolution. The enantiomeric excess of each compound is determined us ing direct liquid chromatographic resolution on chiral cellulose or am ylose phases.