Base-free regio- and stereoselective photochemical synthesis of enol ethers from 1,3-dicarbonyl compounds.

A visible light-induced kinetic controlled regioselective O-alkylation of various 1,3-dicarbonyl compounds with diazoacetates and cyclic ethers has been developed. The protocol provides a green and practical approach to highly stereoselective enol ethers under mild and base-free conditions in good to excellent yields.