ORGN 221

The rich functionalities(i.e. the epoxide, olefin and ester functional groups) in gamma,delta-epoxy-alpha,beta-enoates provide opportunities for SN2-epoxide opening, allylic substitution, and 1,4-conjugated addtion. These chemo-, regio- and stereoselective reaction could provide versatile methodologies for both heterocyclic and stereocontrolled acyclic syntheses. The opening of the epoxide with AcCl, AcBr, and benzoyl chloride afforded the delta-acyloxy-gamma-halo-alpha,beta-enoates , and subsequent copper-mediated allylic SN2' substitution afforded 5-acyloxy-2-alkyl-3,4-enoates. Stereoselective reaction of Grinard reagents, in the presence of catalytic CuCN, with these 5-acyloxy-2-alkyl-3,4-enoates afford 2,3-di-alkyl-4,5-enoates. The selectivity of these reactions as a function of reaction parameters will be discussed.