The intramolecular cyclization of unsaturated benzo derivatives of Bicyclo[3.3.2]decane

Abstract

When treated with electrophilic reagents the benzo derivatives of bicyclo[3.3.2]decane, 7,11-dimethyl-ene-6,7,8,9-tetrahydro-5,9-propano-5H-benzocycloheptene and 11-methylene-5,6,8,9-tetrahydro-5,9- propano-7H-benzocyclohepten-7-one, both exclusively undergo intramolecular cyclization to form derivatives of 6,7,8,9,10,11-hexahydro-5,9:7,11-dimethano-5H-benzocyclononene (benzohomo-adamantene) in high yield. The latter reactant also cyclizes to form derivatives of 5,6,7,8,9,10-hexa- hydro-5,8:7,10-dimethanobenzocyclooctene (benzohomonoradamantene) when reduced with sodium in moist ether or under Wolff-Kishner conditions.