Question #228f8

1 Answer
Jan 11, 2017

WARNING! Long answer! Here's what I get.

Explanation:

1,1-Dichlorocyclohexane (A)

1,1

This has no chiral carbons, so it is achiral and optically inactive.

cis-1,2-Dichlorocyclohexane (B)

cis-1,2

This has two chiral carbons, but it has an internal plane of symmetry that bisects the #"C1-C2"# and #"C4-C5"# bonds.

It is a meso compound, so it is optically inactive.

cis-1,3-Dichlorocyclohexane (C)

cis-13

This has two chiral carbons, but it has an internal plane of symmetry that passes through #"C2"# and #"C5"#.

It is a meso compound, so it is optically inactive.

cis-1,4-Dichlorocyclohexane (D)

cis-1,4

This has no chiral carbons, so it achiral and optically inactive.

trans-1,2-dichlorocyclohexane (E and F)

trans-1,2

This has two chiral carbons, and it has no plane of symmetry. It exists as a pair of optically active nonsuperimposable mirror-image isomers.

trans-1,3-Dichlorocyclohexane

trans-1,3

trans-1,3-Dichlorocyclohexane has two chiral carbon atoms, and it lacks an internal plane of symmetry.

It is not superimposable on its mirror image. It exists as a pair of optically active nonsuperimposable mirror-image isomers.

trans-1,4-Dichlorocyclohexane (I)

trans-1,4

This has no chiral carbons, so it is optically inactive.

Enantiomers

The enantiomeric pairs are: (E,F) and (G,H).

Diastereomers

The diastereomeric pairs are (B,C), (B,E), (B,F), (B,G), (B,H), (C,E), (C,F), (C,G), (G,H), (E,G), (E,H), (F,G), and (F,H).

Meso compounds

The meso compounds are B and C.