Complete the following:

Give the major and minor products (C and D).

Explanation

Very strong base butyl lithium react at propargylic H atom and terminal H atom. In the reactant (A), there is no terminal H atom, but there are two propargylic H atoms at `C-2` and `C-5`. Reaction with `BuLi` wth take place at both these C atoms, giving two products.

Alkynide ion(C) is slightly more stable than alkynide ion (B) due to `+I` effect of Me group in (C) and `+I` effect of `Et` group in (B).
More the EDG, less stable is the carbonion. Et group has more `+I` effect than `Me` group.