Question

Question #81755

Answer 1

The ester, A

Explanation:

The alkene is missing an H (the double bond). The carboxylic acid wants to donate its H to somewhere, but CH2Cl2 isn't good at pulling H's away from acids. So, when the alkene lines up just right relative to the acid, the reaction will proceed quickly to the ester (A).

Choices B&C do not account for all of the acid's O's. Choice D would require the one of the alkene's C's to find another O from somewhere, but where?

Answer 2

The product is (B): trans-2,3-dimethyloxirane.

Explanation:

Peroxy acids are oxidizing agents — they convert alkenes to epoxides.

The reaction is stereospecific because of a cyclic mechanism.

With (E)-but-2-ene, the reaction forms two new chiral centres.

Thus, the product is a racemic mixture of (2R,3R)- and (2S,3S)-2,3-dimethyloxirane.