Total synthesis of (±)-erythrocarine using dienyne metathesis

Total Synthesis of (±)-erythrocarine was achieved using ruthenium-catalyzed dienyne metathesis as a key step. A tetrahydroisoquinoline skeleton having tetrasubstituted carbon center was constructed using our method, that is, carbon dioxide and an alkyl group were introduced onto an alkyne having a heteroatom in a tether using the nickel complex to produce α,β-unsaturated carboxylic acid and then isoquinoline skeleton was constructed by Michael reaction of the tethered nitrogen to the resultant α,β-unsaturated ester.