parallel bondsparallel bondsparallel bonds

Drawing Cyclohexane

equatorial bonds

axial bonds

equatorial bonds axial bonds

1 2 3

4

5

6

Start anywhere and number consecutive carbons.

Numbering Cyclohexane

tetrahedral carbon

1

Tetrahedral Carbons in Cyclohexane

tetrahedral carbon

2

tetrahedral carbon

3

tetrahedral carbon

4

tetrahedral carbon

5

tetrahedral carbon

6

1 2 3

4

5

6

6 axial bonds (green) (3 straight up; 3 straight down)

6 equatorial bonds (blue) (3 slightly up; 3 slightly down)

12

Disubstituted Isomers of Cyclohexane

and . . .

two equatorial substituents (purple)name of cpd: trans-1,2-di . . . cyclohexane

two axial substituents (purple)name of cpd: trans-1,2-di . . . cyclohexane

1

2

are conformational isomers of one another.

Also, . . .

1 3

and . . .

two equatorial substituents on carbons 1 & 3 name of cpd: cis-1,3-di . . . cyclohexane

1

3

two axial substituents on carbons 1 & 3 name of cpd: cis-1,3-di . . . cyclohexane)

are conformational isomers of one another.

Furthermore, . . .

1

4

two equatorial substituents on carbons 1 & 4 name of cpd: trans-1,4-di . . . cyclohexane)

and . . .

1

4

two axial substituents on carbons 1 & 4name of cpd: trans-1,4-di . . . cyclohexane

are conformational isomers of one another.

flip this C above the plane

flip the other C below the plane

hold red bonds in a plane

the other chair conformation

you get

Chair Conformations of Cyclohexane

number carbons in thisconformation

12

3

45

6

number the same carbons in this conformation 1

23 4

56

12

3

45

6

1

23 4

56given the plane

formed by carbons2, 3, 5, and 6

C1 is below the planeand ...

C4 is above the plane,while...

C1 is above the plane and...

C4 is below the plane.

21 3

456

2

61

4

5

3equatorial bondshere become ...

axial bonds here, and...equatorial bonds here.

axial bondshere become ...

1 2 3

4

5

6

Equatorial bonds alternate being above and below the axial bonds on a given carbon atom

above

above

below

below

below

above

and . . .

1 2 3

4

5

6

axial bonds alternate being above and below the equatorial bonds on a given carbon atom.

above

below

belowbelow

above

above

The End

And what a nifty cool story it was . . .