Functionalization of (-)-β-pinene and (-)-limonene via cross metathesis with symmetrical internal olefins

The straightforward functionalization of sterically demanding α,α-disubstituted double bonds of the natural products β-pinene and limonene via cross metathesis with symmetrical internal olefins is described. The reaction is catalyzed by Hoveyda-Grubbs type ruthenium catalysts in dimethyl carbonate as green solvent and makes possible the clean introduction of ester and nitrile groups in one step without formation of byproducts.