Heterosubstituted or functionalized derivatives of 1- and 2-(trifluoromethyl)naphthalenes emanating from aryne adducts

More than two dozen new CF3-substituted naphthalene derivs. were prepd. in an expedient way by employing 3- and 4-(trifluoromethyl)benzyne as the key intermediates. 2- And 4-Chlorobenzotrifluoride were treated with butyllithium and the organometallic species thus generated were allowed to decomp. in the presence of furan. The resulting cycloadducts were reduced to the (trifluoromethyl)naphthalenes, ring-opened to the (trifluoromethyl)naphthols and transformed to the dibromo adducts. The latter were stereoselectively converted into the bromo-1,4-epoxy-1,4-dihydro(trifluoromethyl)naphthalenes and, by deoxygenation, into various bromo(trifluoromethyl)naphthalenes. Trifluoromethyl substituted naphthoic acids were obtained when the bromo compds. were subjected to a halogen/metal permutation followed by carboxylation. [on SciFinder (R)]