Question

Draw the major organic product of the following reaction.

Answer 1

General guidance

Concepts and reason

Epoxides (cyclic ethers) are reactive towards nucleophile due to the ring strain present in the structure. They undergo chemical reactions with both acids and bases. Both chemical reactions result in the formation of an alcohol.

Fundamentals

Grignard reagent is a strong nucleophile, it attacks on the less substituted side of the epoxide ring and generates an anion which on treatment with aqueous acidic solution gives corresponding alcohol.

Step-by-step

Step 1 of 2

Nucleophilic attack of ethyl anion on the less substituted carbon of epoxide ring.

H3C CH2MgBr CH 2 CH H2C 3 CH CH3 2

Explanation | Common mistakes | Hint for next step

Epoxides are highly reactive towards acids and bases due to the ring strain direct attachment of carbon with oxygen generates a partial positive charge on the carbons. In case of unsymmetrical epoxides, the nucleophile will attack at the less substituted carbon to avoid the steric hindrance.

Step 2 of 2

The oxygen will abstract the proton from the solution in order to neutralize the negative charge which results in the formation of an alcohol.

Major product of the reaction is as follows:

Explanation

The negative charge on oxygen is neutralized by the protonation and the product is turned out to be an alcohol.

Answer

Major product of the reaction is as follows:

Answer only

Major product of the reaction is as follows: