The versatile reactivity of the electrophilic fragment Cp*Ru+ toward unsaturated acyclic hydrocarbons is described: stoichiometric cyclization with 1,3,5-hexatriene and metathesis with 1,7-octadiene as well as catalytic isomerization and/or oligomerization with 1,4-pentadiene, 1,5-hexadiene, 1-hexene, and neohexene. In the case of neohexene, a novel reaction catalytically producing CH4 and C-11 and C-17 hydrocarbons is reported.