“…The fragment with highest mass appeared at m/e 371 which was due to loss of a chlorine from the molecular ion (M+ -Cl). The remainder of the spectra in all cases were in conformity with previous studies on similar molecules (Benson et al, 1971; Knox et al, 1973;Onuska and Comba, 1975), involving further losses of Cl, HC1, or their com- was present at m/e 373. The similarity of mass spectra in conjunction with identical retention times on GLC columns and closeness of behavior on thin-layer plates (Table II) showed that PC I and PC II were isomeric molecules.…”