Synthesis of α,β-disubstituted cycloalkenones through a sequence of olefin metathesis and oxidative rearrangement

Efficient syntheses of five-, six-, and seven-membered α,β-disubstituted cycloalkenones were achieved. Ring-closing metathesis and allylic oxidative rearrangement were the key steps in this route. To make substituted cycloalkenes from triene substrates constituted of two monosubstituted double bonds and one α,α-disubstituted double bond, ethylene was found to successfully promote equilibria among ring closing-ring opening-ring closing processes.