Redox-triggered C-C coupling of diols and alkynes: synthesis of β,γ-unsaturated α-hydroxyketones and furans by ruthenium-catalyzed hydrohydroxyalkylation.

Direct ruthenium-catalyzed CC coupling of alkynes and vicinal diols to form β,γ-unsaturated ketones occurs with complete levels of regioselectivity and good to complete control over the alkene geometry. Exposure of the reaction products to substoichiometric quantities of p-toluenesulfonic acid induces cyclodehydration to form tetrasubstituted furans. These alkyne-diol hydrohydroxyalkylations contribute to a growing body of merged redox-construction events that bypass the use of premetalated reagents and, hence, stoichiometric quantities of metallic by-products.