It WRS demonstrated that 2, &dibromohydroquinone can be selectively mono-0-alkylated at either the 1 or 4 oxygen depending on whether the monoanion or dianion is being alkylated. The monoanion alkylates preferentially at the I oxygen and the dianion at the 4 oxygen. The selectivity in each case is increased on changing from water to dimethyl sulfoxide and this difference in selectivity is attributed mainly to solvation effects. 2, 6-and 3, 5- ...
