Question

What alkyl halide forms each of the following alkenes as the onlyproduct in an elimination reaction?

a.

b.

c.

d.

Short answer

The major alkyl halide as the reactants are shown below:

Step-by-step solution

Position of  β hydrogen

The $\mathbf{\text{β}}$ hydrogen position will be such that it exclusively forms the product provided.

Position of the leaving group

The leaving group position decides the product formation. Both the leaving group and $\text{β}$ hydrogen are in an antiperiplanar position.

Based on the mentioned steps, the following alkyl halides are drawn.

Representation of the possible alkyl halide from a

Representation of the possible alkyl halide from b

Representation of the possible alkyl halide from c

Representation of the possible alkyl halide from d