Organic Chemistry

Cycloalkanes

Figure 72

cis-1,2-dichlorocyclohexane Figure 73trans-1,2-dichlorocyclohexane

1(R),2(S)-dichlorocyclohexane 1(S),2(S)-dichlorocyclohexane

Conformers, or conformational isomers, are different arrangements of the same molecule
in space. Do not confuse them with any kind of true isomer as they are in every way the
same molecule. The difference is in how the molecule is bent or twisted is space in any one
instant of time.

26.5 Cyclohexane

The first molecule that is generally presented in a discussion of cycloalkane conformers is
cyclohexane. It comes in several flavors; the main ones are the chair conformation and the
boat conformation.

Figure 74

Figure 75

Boat conformation

Chair conformation