Synthesis of functionalized lactones: catalytic cross-coupling of 1,2-diols and allylic alcohols.

Simple industrial feedstock chemicals such as allylic alcohols and 1,2-diols are cross-coupled to deliver δ-hydroxybutyrolactones. The reaction occurs through O-H bond activation via amine-amide metal-ligand cooperation involving allylic aldehydes, radical intermediates, and Ru(III) species, as established by EPR studies. This tandem process proceeds with the liberation of molecular hydrogen as the only green byproduct.