Question

Draw all possible constitutional and stereoisomers for a compound of molecular formula${\mathbf{\text{C}}}_{\mathbf{6}}{\mathbf{\text{H}}}_{\mathbf{12}}$ having a cyclobutane ring and two methyl groups as substituents. Label each compound as chiral or achiral.

Short answer

The possible constitutional isomers of the compound are given below:

The possible stereoisomers of the compound are given below:

The structures A, B, D, F, and G are achiral, and the structures C and E are chiral.

Step-by-step solution

Constitutional isomers

Another name that is utilized to denote constitutional isomers is “structural isomers”. A particular kind of constitutional isomer is a functional isomer.

Stereoisomers

Stereoisomers can be designated another name which is noted as “spatial isomers”. Enantiomers belong to the category of stereoisomers.

Constitutional and stereoisomers of C6H12 

There are three constitutional isomers for the compound ${\text{C}}_6{\text{H}}_{12}$possessing a cyclobutane ring and two methyl groups. The constitutional isomers are given below:

Constitutional isomers

Structure A has a plane of symmetry and will be optically inactive. Hence, structure A is achiral. The plane of symmetry in compound A can be given as follows:

Plane of symmetry in compound A

The structure B contains a plane of symmetry and is optically inactive. Hence, structure B is achiral.

Plane of symmetry in compound B

The structure C does not contain a plane of symmetry and is optically active. Hence, structure C is chiral.

There are four stereoisomers for the compound with a formula ${\text{C}}_6{\text{H}}_{12}$comprising a cyclobutane ring and two methyl groups. The stereoisomers can be given as follows:

Stereoisomers

The structure D possesses a plane of symmetry and is optically inactive. Hence, compound D is achiral.

Plane of symmetry in compound D

The structure E does not possess a plane of symmetry and is optically active. Hence, compound E is chiral.

The structure F has a plane of symmetry and is optically inactive. Hence, compound E is achiral.

Plane of symmetry in compound F

The structure G does not comprise a chiral carbon as four varied functional groups are not linked to the carbon atom. Hence this compound is achiral.