Acid‐catalyzed Reactions of Aromatic Hydrocarbons with Alkanes and Cycloalkanes. X. Alkylations with Cyclohexane The complex reaction mixtures of the nonconventional alkylation of benzene with cyclohexane in the presence of Lewis/proton acids and promotors were investigated by gas‐liquid chromatography and mass spectrometry. Four representative groups of hydrocarbons were found including cycloalkylbenzenes, substituted indanes or tetralines (C12H16), C1‐C6‐alkylbenzenes and isomeric biscycloalkyls (C12H22). Their formation is interpreted as a competition between alkylation, (without or with isomerization), ringfission with cycloalkylation or fragmentation, and self‐alkylation; phenylcycloalkylcations and phenylalkylcations are the intermediates.