Question

In each reaction box, place the best reagent and conditions from the list below.

In each reaction box, place the best reagent and conditions from the list below.

Answer 1

Concepts and reason

Alkenes and alkynes are very reactive hydrocarbons due to their high electron density. Conversion of alkynes to alkenes is carried out by simple hydrogenation reaction which involves the addition of molecular hydrogen to the alkene in the presence of metal catalyst whereas conversion of alkenes to alkynes is complicated and involves the series of reactions.

Fundamentals

Alkenes are unsaturated hydrocarbons with one or more than one double bonds and alkynes are unsaturated hydrocarbons with triple bonds between two carbon atoms. Alkenes undergo a series of chemical reactions in order to form an alkyne. This can be done by removal of hydrogen atoms from carbons having double bonds.

The alkene on reaction with bromine results in the formation of disubstituted product which is a vicinal dihalide.

Sodamide on reaction with vicinal dihalide gives an alkyne.

Alkyne on reaction with one equivalent of sodamide gives an anion which reaction with methyl bromide results in the formation of final product.

Ans:

The best conditions for the conversion is,