TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The dehydrocyclization catalyst is selected from alumina-based catalysts; silica-based catalysts; bismuth oxides; lead oxides; antimony oxides; chromium treated alumina; rhenium treated alumina; platinum treated zeolites; a mixture of chromia-alumina and bismuth oxides; bismuth oxides, lead oxides or antimony oxides in combination with supported platinum, supported palladium, supported cobalt, and/or metal oxides; supported chromium on a refractory inorganic oxide; rhenium oxide or metallic rhenium deposited on a neutral or weakly acidic support; and/or platinum deposited on aluminosilicate MFI zeolite.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: When the renewable 4-5C molecules comprise renewable isobutanol, the step (c) involves oxidizing the isobutanol to form renewable isobutyraldehyde, then condensing the renewable isobutyraldehyde with a 4C reagent to form renewable 2,5-dimethyl-3-hexene. When the renewable 4-5C molecules comprise a 5C alcohol (preferably 3-methyl-1-butanol), the step (c) involves dehydrating the 5C alcohol to form renewable 3-methyl-1-butene, then contacting the 3-methyl-1-butene with a metathesis catalyst to form renewable 2,5-dimethyl-3-hexene. The metathesis is carried out under conditions where ethylene is removed, thus providing purified renewable 2,5-dimethyl-3-hexene. The purity of the renewable 2,5-dimethyl-3-hexene is at least 50%. The dehydrating is carried out in the presence of dehydration catalyst. When the renewable 4-5C molecules comprise a diolefin, then step (c) comprises carrying out metathesis of the diolefin to form renewable 2,5-dimethyl-1,3,5-hexatriene. The diolefin is isoprene. The metathesis is carried out under conditions where ethylene is removed, thus providing purified renewable 2,5-dimethyl-1,3,5-hexatriene. The purity of the renewable 2,5-dimethyl-1,3,5-hexatriene is at least 50%. The metathesis is carried out in the presence of a metathesis catalyst. The renewable 2,5-dimethyl substituted-6C olefins comprise 2,5-dimethyl-1,3,5-hexatriene, 2,5-dimethyl-3-hexene or 2,5-dimethyl-2,4-hexadiene. When the renewable 5C molecule comprises a renewable 5C alcohol, then the reacting in step (c) involves dehydrating the renewable 5C alcohol to form renewable pentene, then dehydrogenating the renewable pentene to form renewable isoprene, then contacting the renewable isoprene with a metathesis catalyst to form renewable 2,5-dimethyl-1,3,5-hexatriene. The dehydrogenating and aromatizing of step (d) are carried out in a single reaction zone or in at least two reaction zones. The process further involves purifying the renewable 2,5-dimethyl substituted-6C olefins prior to the dehydrogenating and aromatizing of step (d). The p-xylene is isolated. EXAMPLE - No suitable example is given.