Question

Predict the major product of the following reaction:

And select the major product:

• A.
• B.
• C.
• D. None of the above

Answer 1

The correct option is C

This is clearly an intermediate step for Hofmann elimination. The substrate – which is a salt – contains the base $O{H}^{-}$ as a part of it and the heat given according to the reaction points towards $\beta$-elimination. The only question, which $\beta$-hydrogen will be abstracted by the hydroxide base?
The Hofmann product, unlike the Zaitsev product, is one that is obtained based on the abstraction of the $\beta$-hydrogen that is the least hindered. So the hydrogen attached to the homocyclic (cyclohexane) carbon is not abstracted. Any one of the 6 equivalent $\beta$-hydrogen atoms are removed from the two equivalent (in terms of abstraction of $\beta$-hydrogen) methyl groups attached to the $\alpha$-carbon.

The above product is the overwhelming major product! The following is not formed.