A FLEXIBLE STEREOCONTROLLED SYNTHESIS OF BETA-HYDROXY-ALPHA-METHYL ESTERS - APPLICATION TO THE SYNTHESIS OF STEGOBIOL AND SERRICOROLE

beta-Hydroxy-alpha-methyl esters have been obtained in a purity from c ommercially available methyl 3-oxopentanoate and stereocontrolled mann er and high enantiomeric and diastereomeric methyl 3-oxobutanoate. The key step is the catalytic hydrogenation of the carbonyl group using ( R)- or (S)-BINAP-Ru as chiral catalyst followed by asymmetric alkylati on. Stegobiol and serricorole, components of the sex pheromone of the drugstore beetle, Stegobium paniceum (L.) and cigarette beetle, Lasiod erma serricorne (F.), have been prepared from these chiral building bl ocks without the need for stoichiometric amounts of chiral auxiliaries .