Processes for the conversion, under conditions and with a catalyst system effective for olefin metathesis, of hydrocarbon feedstocks comprising an acyclic symmetrical olefin (e.g., butene-2) are described. Olefin products of lower and higher carbon numbers (e.g., propylene and pentene) are formed in the presence of a catalyst comprising a solid support and a tungsten hydride bonded to alumina present in the support. This occurs despite the olefin metathesis reaction mechanism leading to a degenerative result, without any expected production of different carbon number products from acyclic symmetrical olefins.