Question

What reagents would you use for the following synthesis?

a. (Z)-3-hexene from 3-hexyne

b. (E)-3-hexene from 3-hexyne

c. hexane from 3-hexyne

Short answer

a.H₂/ Lindlar catalyst

b. Na, NH₃ (liq), -78˚C

c.Excess H₂, Pd/ C

Step-by-step solution

Step 1:

3-hexyne undergoes hydrogenation in presence of Lindlar’s catalystto form (Z)-3-hexene.

Step 2

3-hexyne reacts with Na, NH₃(liq) at -78˚C to form (Z)-3-hexene.

Step 3:

3-hexyne reacts with excess H₂ in presence of Pd/ C to form (Z)-3-hexene.