"A carbonyl transposition can be effected via the addition of a vinyl or an alkyl Grignard reagent to an α,β-unsaturated ketone. Acid-catalyzed rearrangement of the resultant allylic alcohol during oxidation with PCC affords the transposed α,β-unsaturated carbonyl substrate. This reaction represents a useful alternative when Wittig olefination of the ketone is problematic. Tertiary bis(allylic) alcohols are oxidized by PCC or PDC to the carbonyl transposed dienones. Addition of silica gel (SiO2) to the PCC reaction greatly facilitates the workup, and application of ultrasound enhances the rate of the reaction and the yield of the product."