Eine einfache Synthese makrocyclischer Kohlenwasserstoffe durch Metathese von Cycloolefinen

A Simple Synthesis of Macrocyclic Hydrocarbons by Metathesis of Cycloolefins Metathesis of cycloolefins normally leads to unsaturated polymers. Using rheniumheptoxide on alumina, activated by tintetramethyl and working in dilution via soxhlet-similiar circulation system the metathesis reaction was directed to macrocyclic dienes, which are the dimers of the initial cycloolefins. Starting with C₇-, C₉- and C₁₀-cycloolefins symmetric macrocyclic C₁₄-, C₁₈- and C₂₀-dienes are obtained in yields of 58-74%. The metathetic dimerization of cyclooctene leads to 1.9-cyclohexadecadiene in a yield of 30%. By hydrogenation at room temperature and normal hydrogen-pressure all cyclodienes were converted quantitatively to cycloalkenes (catalyst: potassium on alumina) or to cycloalkenes (catalyst: palladium on carbon).