The 1H NMR spectrum of 6 taken at ambient temperature consisted of a sharp singlet at 6 2.50 for the four methyl groups and a broad singlet at 6 4.94 for the methylene protons. lSJ9 The 1% NMR spectrum of 6 consisted of only five lines, readily assigned to the methyl carbons, the methylene car-bons, and three sets of aromatic carbons (see Experimental Section). Consequently 6 had to have a symmetric structure, with the chloromethyl groups ...
