Question

For the following SN2 reaction, draw the organic and inorganic products of the reaction, and identify the nucleophile, substrate, and leaving group. Include wedge/dash bonds and H on a stereocenter.

Select the statement that properly identifies the nucleophile, substrate, and leaving group.

Answer 1

Concepts and reason

The ${{\rm{S}}_{\rm{N}}}2$ reaction of a compound with methoxide ion is given and the products need to be drawn. Also, the substrate, nucleophile and leaving group needs to be mentioned.

Draw the product via the attack of the nucleophile from the backside of the substrate while removing the leaving group simultaneously to get the product.

Fundamentals

${{\rm{S}}_{\rm{N}}}2$ reaction: It stands for substitution nucleophilic bimolecular reaction. The reaction is a single step and the removal of halide ion and the attack of the incoming nucleophile occurs in the same step. Hence, the rate is dependent on the concentration of both the species. The reaction proceeds via the formation of transition state.

A general mechanism is shown below:

In an ${{\rm{S}}_{\rm{N}}}2$ reaction, the product formed has configuration opposite to that of reactant as the nucleophile attacks from the side opposite to the leaving group. Therefore, if given reactant molecule has R configuration, then the product has S configuration and vice versa. Hence, it is stereospecific in nature.

The substitution product is as follows:

The substrate is ${\rm{C}}{{\rm{H}}_3}{\rm{C}}{{\rm{H}}_2}{\rm{Br}}$ , ${\rm{C}}{{\rm{H}}_3}{{\rm{O}}^ - }$ is the nucleophile and ${\rm{B}}{{\rm{r}}^ - }$ is the leaving group as shown below.

Ans:

The products are as follows: