Recently, Franzus and Hudson (3), and Russell and co-workers (4) reported an extensive study of 1,3-dibroinocyclohexanes and 1,3-and 1,4-dichlorocyclohexanes. Acidic treatment, with either hydrobromic acid or hydrochloric acid of 1,4-(or 1,3-) cyclohexanediols yielded cis-trans mixtures of dihalogen-substituted cyclohexanes.The bulk of our product (FI), when isolated and recrystallized from ethanol, melts a t 102-103", in agreement with trans-l,4-dichlorocyclohexane prepared by Russell and co-workers by a similar procedure. Proton magnetic resonance spectra show a peak a t T = 5.9 (Russell et al. T = 5.82), due to the methine protons in 1,4-dichlorocyclohexane, the C-1 and C-4 protons being predominantly diaxial. Proton magnetic resonance spectra of F 4 showed presence of trans-1,4-dichlorocyclohexane (T = 5.9) and a pealc a t T = 5.67, consistent with the signal due to methine protons of trans-1,3-dichlorocyclohexane (4). The reaction between 1,4-cyclohexanediol and hydrochloric acid uTas then followed up in the manner described below.A series of Carius tubes each containing 0.98 moles of the diol and 4.1 moles of hydrochloric acid were sealed and heated a t 80-90'. At regular intervals one tube was cooled, and the reaction nlixture worked up as described a t the beginning of the note. The isolated products were then analyzed by n.1n.r. (30y0 carbon tetrachloride solution, int. TJIS). In addition to unreacted material, 4-cl~lorocyclohexanol, 1,4-dichloroc~~clol~exane, peaks a t T = 4.45 and T = 2.9 appeared. The T = 4.45 pealc is consistent with formation of l,4-cyclohexadiene and the T = 2.9 peal; is consistent with formation of aromatic byproducts. Presence of 1,3-dichlorocyclohexane in our F4 fraction can thus be explained as due to the random addition of hydrochloric acid across the double bonds in 1,4-cyclohexadiene.1. L. I\T. O\\.ES and P. .-I. Ronlxs.