Question

Draw the major product formed when HBr reacts with the following epoxide. Use wedge/dash bonds, including H's at each stereogenic center, to show the stereochemistry of the product.

Answer 1

Concepts and reason

The given problem, based on the concepts of epoxide ring opening by nucleophile, follows second order nucleophilic substitution reaction.

The three-membered cyclic ring contains two hybridized carbon atoms and one hybridized oxygen atom that moiety is represented as epoxide. Epoxides are also known as cyclic ethers. The opening of epoxide follows attack. It depends on the type of nucleophile present.

Fundamentals

In the presence of a weak nucleophile, the nucleophile attacks epoxide on a more substituted site, and follows an type reaction.

Example:

In the presence of a strong nucleophile, the nucleophile attacks epoxide on a less substituted site, and follows a type reaction.

Example:

Ans:

The structural formula of the major organic product is as follows: