(5E)-Prostaglandin E2 (7) was synthesized fron (R)-4-t-butyldimethylsilyloxy-2- cyclopentenone (1) by in situ 2-alkenyloxycarbonylatlon of the organocopper conjugate- addition adduct (3) followed by intramolecular palladium-catalyzed decarboxylative allylic alkylation. The (5E)-prostaglandin E2 skeleton was also obtained from the β-keto allylic ester (11) by a similar decarboxylative allylic alkylation. The decarboxylative allylic ...