Question

use the curved-arrow notation to indicate the flow of electrons in the reaction. (To draw the arrows, click on the reaction to enter the edit mode, then click on the curved-arrow icion.)

Answer 1

Concepts and reason

The problem is based on nucleophilic substitution reaction. Epoxides are the three membered ring structures that have one of the vertices occupied by an oxygen atom. Due to a considerable amount of strain, the epoxide ring tends to open on the attack of a nucleophile.

Fundamentals

Nucleophilic substitution reactions are the reactions in which a nucleophile attacks an electrophilic center and substitutes itself in place of the leaving group. Nucleophiles are the electron rich species that can donate a pair of electron to the electrophilic center. Epoxides act as electrophiles due to the ring strain in the three-membered ring. In order to relieve this ring strain, the epoxide ring opens up on the attack of the nucleophile at the carbon center.

Epoxide ring is a strained system. It acts as the electrophile. Cyanide acts as the nucleophile due to the presence of lone pair of electrons.

Carbon end of cyanide attacks on the carbon of epoxide ring that facilitates the ring opening in the epoxide.

Ans:

The curved arrow notation that indicates the electron flow is as follows: