Q.49 - Organic Chemistry

Question

What alkyl chloride affords the following alkene exclusively under E2 reaction conditions?

Step-by-Step Solution

Answer

The alkyl chloride forms the mentioned alkene is shown below:

Identification of the substrate

The primary halides always favor E2 reactions, whereas the secondary and tertiary halides favor E1 and E2, both depending on the bases used.

So to make the product exclusively an E2 product, a bulky base like potassium-tert-butoxide is used, which takes up a $\text{β}$  proton from the less hindered carbon.

Different types of β hydrogens

Different types of $\text{β}$ hydrogens give different types of elimination products. Here only one type of $\text{β}$ hydrogen is present, so it gives only one product.

So, taking into account all the steps and the types of $\text{β}$ hydrogens present, the possible alkyl halide which undergoes E2 reaction is as follows:

Representation of E2 reaction