Question

Product is:
MCPBA- Meta Chloroperbenzoic acid

A)

B)

C)

D)

Answer 1

Hint:
To answer this question, you must recall the reaction of alkenes with a peroxy acid. Meta- chloroperbenzoic acid is a peroxy carboxylic acid commonly referred to as mCPBA. It is a derivative of meta- chloro benzoic acid.

Complete step by step solution:
As the name suggests, mCPBA is a peroxy acid. A peroxy acid has an oxygen- oxygen bond. It resembles the structure of meta- chloro benzoic acid but has an extra oxygen atom. When reacted with an alkene, it forms epoxides. The reaction has a very key feature that the stereochemistry of the reactant is retained. This means, that if a cis alkene is reacted, a cis epoxide will be formed whereas, a trans alkene will result into the formation of a trans epoxide. The reaction is a stereo selective reaction.
In the question, the given alkene is a cis alkene with both the methyl groups on the same side. We know that the reaction is stereo selective and thus the epoxide formed will be of the same stereochemistry. The product thus formed will be

The correct option is B.

Note:
The reaction is known as Prilezhaev reaction. It proceeds through what is called as the butterfly mechanism. The reaction takes place through the formation of a transition state in which the plane of m-CPBA bisects the plane of the alkene with the oxygen- oxygen bond perpendicular to it. Due to this alignment, frontal orbital interactions occur. We can see this reaction as an electrophilic attack where the peroxy acid is an electrophile and the alkene is nucleophile.