Reactant involved in:• ;Isomerization polymerization of alkenylcyclohexanes1• ;Intramolecular rearrangements of vinylidenecyclopropanes2• ;Cycloisomerization of cyclic and acyclic enynes3Additionally reactant involved in synthesis of biologically active molecules including:• ;Dipeptidyl boronic acid proteasome inhibitors4• ;Substituted 1,3-dihydroindole-2-ones with antitumor effects5• ;Sulfur-free transition state nucleoside analog inhibitors of methylthioadenosine nucleosidase and phosphorylase6