New exocyclic α,β,γ,δ-unsaturated ketones have been synthesized by the base-catalyzed reaction of chromanone, flavanone, their 1-thio analogues and trans-cinnamaldehydes. These unsaturated ketones were reacted with diazomethane at ca. 4 o C to afford spiro-1-pyrazolines in regioselective and stereospecific reaction. Structure and stereochemistry of all these new compounds have been elucidated by combined utilization of various spectroscopic, mainly NMR techniques.

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