There is provided a process for ring opening of aromatics and cycloaliphatics, as well as isomerization of aliphatics. The feedstream to this process comprises hydrocarbons having 6 carbon atoms. The process involves the use of at least two reactors connected in series. The first reactor comprises a zeolite catalyst and is operated under conditions which particularly promote ring opening. The catalyst in this first reactor may comprise zeolite Beta and platinum. A 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. Hydrogen in the effluent of the first reactor may be removed and recycled to the first reactor. Hydrogen required for the second reactor may be satisfied by hydrogen remaining dissolved in the effluent from the first reactor after hydrogen is recycled to the first reactor.