Question

Draw the correct structure(s) for cis-1-bromo-3-methylcyclohexane. Show stereochemistry clearly. To ensureproper grading, explicitly draw all four groups, including wedge/dash bonds, around a chirality center. Indicate whether the compound(s) could exist in an optically active form.

•  could exist in optically active form
• cannot exist in optically active form
• cannot be determined

Answer 1

Concepts and reason

In organic chemistry, the relationship between a pair of compounds can be explained by isomerism. There are two types of isomers: stereoisomers and constitutional isomers.

Stereoisomers are defined as isomers that have the same molecular formula but differ in the spatial arrangement of atoms. Geometric isomerism (also denoting a cis-trans or E-Z isomerism) is a type of stereoisomerism. Cis-trans isomerism is formed when rotation is restricted; wherein there is a carbon-carbon double bond and a cyclic ring system.

Fundamentals

Geometric isomers: Two atoms with the same side location of the double bond are called cis isomers and two atoms with opposiside locations of the double bond are called trans isomers.

In a cyclic compound: The spatial orientation of the disubstituents’ cyclic compound must be viewed as a three-dimentional conformation. Generally, a solid wedge bond indicates it is above the plane of the ring and a broken wedge bond indicates it is below the plane.

The structure of cis-1-bromo-3-methylcyclohexane is given below:

The complete stereo chemistry of given structure is given below:

Ans:

The complete stereo chemistry of the given name of the structure is