Question

a. How many asymmetric centers does the following compound have?

b. How many stereocenters does it have?

Short answer

a) A compound hasoneasymmetric center.

b) A compound has three stereocentres.

Step-by-step solution

Subpart (a) Asymmetric centers

Chiral objects are those objects which have no same mirror images. The mirror images don’t superimpose each other. The compounds whose mirror images superimpose each other that compounds are called achiral objects.

Chiral carbon is that carbon atom that is bonded to four different groups. Here, only Cl substituted carbon is chiral carbon as it has one H-atom, one Cl-atom, one CH₃ , and one CH=CHCH₃ group. As all the substituted groups are different. Therefore, only one carbon is chiral carbonand asymmetric.

Subpart (b) Stereocentres

An atom that has different attached substituents and when these substituents are interchanged, it forms another stereoisomer and the carbon center here is termed as stereocenter. Also, all asymmetric centers are stereocentres but all stereocentres can’t be asymmetric.

Here, both the double-bonded carbons and Cl substituted carbon are stereocentres. Therefore, the compound has three stereocenters.