Explain why only a substitution product and no elimination product is obtained when the following Compound reacts with sodium methoxide:

Substitution reaction is a nucleophilic reaction where the Nucleophilic attack and bond breaking between carbon and electronegative group happens either in a step manner or simultaneously.

Example: SN¹ and SN² reaction.

Mechanism of SN² reaction is given above.

Elimination reaction is basically a reaction between alkyl bromide and a base in a step-by-step manner or in a concerted mechanism of bond breaking and making. During the elimination reaction, The C-X (X=halogen) and C-H bond should be in anti-periplanar fashion.

Example: E1, E2 E1cB mechanism.

Mechanism of E1 reaction is given above.

To occur the elimination reaction, The C-X and C-H bond should be in trans periplanar orientation. In the structure given below, The C-Br and C-H bonds are in cis orientation for which elimination doesn’t occur in this case.

So, only substituted product happen in this case.