Question

Draw the major E2 elimination products from each of the following alkyl halides.

a.

b.

Short answer

The major E2 products from the alkyl halides are shown below:

Step-by-step solution

Types of different β hydrogens

The different types of $\text{β}$hydrogens give different types of products.

Representation of beta Hydrogens

Anti-periplanar position

The leaving group and $\mathbf{\text{β}}$hydrogen must be trans to each other(anti-periplanar position). The elimination reaction will take place in those where anti-periplanar orientation is maintained.

Representation of anti-periplanar orientation

Elimination products

Hence, the major E2 products from the alkyl halides are shown below:

Elimination product from a

By maintaining the anti-periplanar geometry, only one possible product is obtained.

Elimination product from b

Only one possible product is obtained while maintaining the anti-periplanar geometry.