Abstract: There is provided a process for ring opening of aromatics or cycloaliphatics, as well as isomerization of aliphatics. The feedstream to this process comprises hydrocarbons having 6 carbon atoms. The process involves the use of a recycle stream containing a source of chlorine, such as carbon tetrachloride, and this process involves the use of at least two reactors connected in series. The first reactor comprises a ring opening catalyst and is operated under conditions which particularly promote ring opening. The catalyst in this first reactor may comprise zirconia modified with tungstate and platinum. A second, downstream reactor is operated under conditions to promote isomerization of aliphatics. The catalyst in the second reactor may comprise alumina, platinum and a chloride component. The catalysts in both the first and second reactors are chlorine resistant.