Question

Predict the structure of product in the above reaction :

Answer 1

The catalytic reduction of (E)-hept-2-en-5-yne gives $(2E,5E)-$hepta$-2,5-$diene. In this reaction, the triple bond is reduced to double bond.

But double bond is not reduced. This is possible only when Lindlar's catalyst (palladium supported on barium sulphate) is used.