Question

a. Locate the stereogenic centres in the ball-and-stick model of lisinopril, a drug used to treat high blood pressure.

b. Label each stereogenic centre as R or S.

Short answer

a.

b.

Step-by-step solution

Stereogenic center

The stereogenic center is the center where four different groups are attached.

R and S nomenclature

The R and S nomenclature is obtained by giving the ranking according to the priority.

The clockwise rotation is known as R configuration, and anticlockwise rotation is assigned as S configuration.

Skeletal structure of Lisinopril

The skeletal structure of Lisinopril is shown as:

Explanation

a. In the given compound, there are three stereogenic centers.

Stereogenic centers

b. The order of priority of the groups at chiral centers are shown as:

$\text{NH>COOH>R>H}$

Therefore, all the movements in lisinopril are anticlockwise. Therefore, all the stereogenic centers are S.

Configurations of Stereogenic centres