ChemInform Abstract: A Novel Cyclodimerization of α,β-Unsaturated Carbonyl Compounds Promoted by Ytterbium Metal.

ChemInform Abstract

Treatment of chalcone (I) with metallic ytterbium and subsequent work-up with water or deuterium oxide produce a mixture of the benzoyltriphenylcyclopentanols (III) and the ketones (IV). When the reaction of (I) with ytterbium is quenched with trimethylsilyl chloride (V), the trimethylsilyl enol ethers (VI) and (VII), together with the dimer (VIII), are formed. The isomeric unsaturated ketones (IX) and (XI) are also cyclized, yielding the cyclopentanol (X) or the cyclohexanone (XII). Ytterbium-promoted cyclodimerization of the methyl phenylacrylate (XIII) leads to the formation of the diphenyloxocyclopentanecarboxylate (XIV).