When (1-bromoethyl)cyclohexane is heated in methanol for an extended period of time

Step 1 of 5

Unimolecular nucleophilic substitution reaction

Nucleophilic substitution reactions in two steps are called unimolecular substitutions or  reactions. In  the mechanism, the substrate forms a carbocation in the first step, which reacts with a nucleophile in the second step to form the substituted product. The carbocation formation is the rate-determining step of the reaction, and therefore  reactions are first-order reactions.

Unimolecular elimination reactions

Elimination reactions that include two steps, namely, an ionization step and deprotonation step, are called unimolecular elimination. In this mechanism, the leaving group is removed first, forming a carbocation from which a beta proton is removed to form an alkene.