1: Grubb's 2nd generation catalyst / dichloromethane / 3 h / Reflux 2: tert.-butylhydroperoxide; bis(acetylacetonate)oxovanadium / 1,2-dichloro-ethane / 2 h / 0 - 20 °C 3: 1H-imidazole / N,N-dimethyl-formamide / 2 h / 20 °C 4: 2,2,6,6-tetramethyl-piperidine; n-butyllithium; diethylaluminium chloride / hexane; toluene / 20.25 h / 0 °C / Inert atmosphere View Scheme