Reaction between benzene or chlorobenzene with the double bond of certain phospholene derivatives occurs in the presence of aluminum doride at rmm temperature to yield &arylated phospholanes. Phospholene derivatives employed in such reactions have included 1, 3- dimethyl-3-phospholene oxide, 1-hydroxy-3-phospholene oxide, l-methylhexahydro-A3- phosphindole oxide and its Ah" isomer, l-methyl-6-methoxyhexahydro-A~ 1a- ...