dehydrorotenoid (1) was successfully achieved via an intramolecularaldol reaction of the corresponding 1,2-diaryl diketone intermediate. The 1,2-diaryl diketone was prepared using a ruthenium-catalyzed oxidation of the corresponding substituted diaryl acetylene. Treatment of this 1,2-diketone with l-proline induced a selective intramolecularaldolcondensation reaction, forming the desired benzopyranone over