Question

What product(s) are expected in the ethoxide-promoted ?-elimination reaction of 2-bromo-2,3-dimethylbutane? Omit ions, salts, and ethanol from your response.

Answer 1

Concepts and reason

The product of the $\beta$ elimination reaction of 2-bromo-2,3-dimethylbutane needs to be given. The base used is ethoxide ion. Draw the structure and abstract the hydrogen that gives more substituted as well as less substituted product to get the two products.

Fundamentals

E2 reaction: It stands for elimination reaction following second order kinetics. In E2 reaction, the base abstracts the $\beta$ hydrogen and removal of the leaving group simultaneously in the same step. A general mechanism is shown below:

The $\beta$ hydrogens in 2-bromo-2,3-dimethylbutane are as follows:

The major product is as follows:

The minor product is as follows:

Ans:

The products of the reaction are as follows: