Enantiospecific synthesis of tetrasubstituted delta-lactones

For investigations concerning the selectivity of polyketide synthases (PKSs ) which have been rationally engineered through genetic techniques the synt hesis of substituted delta-lactones is of great importance. An enantiospeci fic route towards eight of the possible sixteen stereoisomers was developed which is also readily adaptable for the introduction of alkyl modification s and isotopic labels. (C) 1998 Published by Elsevier Science Ltd. All righ ts reserved.