Ru-catalyzed intermolecular [3+2+1] cycloaddition of alpha,beta-unsaturated ketones with silylacetylenes and carbon monoxide leading to alpha-pyrones.

Ruthenium catalyzes a carbonylative [3+2+1] cycloaddition, using silylacetylenes, alpha,beta-unsaturated ketones, and CO as the starting materials, providing the new method for the synthesis of tetrasubstituted alpha-pyrones. In this reaction, the carbonyl group and alpha-carbon of vinyl ketones are incorporated as a three-atom assembling unit. [reaction: see text].