Abstract: Lithium ( α-caralkoxyvinyl) (2-thienyl) mixed higher order cyanocuprate(3), prepared by addition reaction of ethyl propiolate with ( n-C₁₃H₂₇ ) (2-thienyl) CuCNLi₂(2), was coupled with cis bromopropylene under Pd(PPh₃)-4, gaving ethyl -1-(Z-propylidene)-2-furanone(1) was then selectively synthesized through epoxidation of the diene ester with m chloroperbenzoic acid as oxidant and stereospecific lactonation by acid catalysis. The title compound(1) showed E: Z >98:2 and cis:trans >96:4. The method proposed has advantages of short route and high yield. Thus a new efficient method is presented for stereo selective synthesis of 3 alkylidene 4,5 dihydro 4 hydroxy 5 methyl 2(3H) furanones.

Key words: Epilitsenolide C₂, alkylidene-dihydro-hydroxy-methyl-furanone, mixed higher order cyanocuprate, steoreoselective synthesis