Question

Predict the major product(s) for the reaction of pent-1-en-4-yne with sodium amide followed by reaction with bromoethane.a. Hept-1-en-4-yne b. Hept-6-en-3-yne c. Hept-3-en-6-yne d. Hept-4-en-1-yne

Answer 1

Answer:

Major product is Hept-1-en-4-yne

Explanation:

Sodium amide ($NaNH_{2}$) gives acid-base reaction with terminal alkyne preferably than terminl alkene. Because terminal alkyne are more acidic due to sp-hybridization of carbon atom.

In the first step, sodium amide first deprotonates pent-1-en-4-yne to produce an alkenylide anion.

In the second step, the alkenylide anion gives a $S_{N}2$ reaction with bromoethane to produce hept-1-en-4-yne.

Full reaction scheme has been shown below.