Estra-4,9-diene-3,17-dione, an important pharmaceutical intermediate, was synthesized by a three-step sequence from δ-lactone 1 in 23.4% overall yield. Reaction of δ-lactone 1 and Grignard reagent 2 followed by treatment with Jones reagent resulted in precursor 4. The domino cyclization reaction of 4 with piperidinium acetate gave estra-4,9-diene-3,17-dione.