Question

Convert propene to propyne.(in steps)

Answer 1

Propene→Br2/dark→1,2-dibromopropane→KOH/alc→2-bromopropene→KOH/acl→Propyne

Answer 2

Explanation :

Step 1 : First propene react with bromine in dark in a solvent such as $CCl_4$ to produce 1,2-dibromopropane as a product. It is an electrophilic addition reaction.

Step 2 : When 1,2-dibromopropane react with strong base like alcoholic KOH result in the formation of prop-1-yne. The alcoholic KOH is a dehydrohalogentating agents.

The reactions are shown below.