Question

What is the reaction of epoxide with Grignard reagent?

Answer 1

Hint: Grignard reagents are organometallic compounds having a metal and an organic group along with a halogen, with the formula, RMgX, where R is any alkyl group, Mg is magnesium and X is halogen. They undergo additional reactions with carbonyl groups. Epoxides are tricyclic compounds having one carbonyl group.

Complete answer:
Grignard reagents are highly basic organometallic compounds. They have the tendency to react with any species that donates a proton. Grignard reagents are capable of generating a nucleophile, which can react with electrophiles in addition to reactions. On the other hand, epoxides are tricyclic compounds having 2 carbon and 1 oxygen atoms. They, when undergoes addition with Grignard reagents, leads to the ring opening of the epoxides.
The reaction of epoxide with Grignard reagents leads to the formation of primary alcohols, with two carbons more than the length, due to the ring opening. The reaction of epoxide with Grignard reagents is:

Epoxide opens as the electrophile is generated by the addition of the alkyl group by Grignard reagent on epoxide. This when subjected to acidic conditions leads to the formation of a primary alcohol.
Hence, reaction of epoxides with Grignard reagent generates primary alcohols.

Note:
Epoxides are also called ethylene oxides. The reaction follows the mechanism of nucleophilic substitution, which is ${S_N}^2$ type. The strong basic condition of the Grignard reagent is responsible for the opening of the ring of the epoxides. The acid workup is the final step in the reaction of epoxides. Apart from reaction with epoxides, Grignard also reacts with aldehydes, ketones, acid chlorides, etc. compounds with a carbonyl group.