N, N-Dibromourethan (DBU) was prepared. The addition of DBU to styrene gave an anti-Markownikoff's adduct, (2). The orientation of the addition of DBU is thus similar to that of N, N-dichloro analogue (DCU) and opposed to that of N, N-dibromobenzenesulfonamide (DBBS). Reactions of DBU, DCU, and DBBS or N, N-dibromo-p-toluenesulfonamide with 1, 2-dihydronaphthalene were examined in which DBBS gave desired adduct, (5), in good yield whereas DCU and DBU gave no normal adduct but complex mixtures. Reaction of methyldihydronaphthalenes with these reagents gave similar results. Compound (2) was converted to 1-bromo-2-benzenesulfonamido (7), and 1-alkoxy-2-benzenesulfonamido-1, 2, 3, 4-tetrahydronaphthalenes (8 and 9).