Substituent Group on the first or third propane

R

|

C-C-C       

Substituent Group of a propyl attached on the second carbon

R

|

C-C-C

Substituent Group attached to the main chain with the first or fourth carbon

R

|

C-C-C-C

Substituent Group of a butyl attached to the main chain by the second carbon of the butyl group

C-C-C-C

    |

   R

Removing the carbon chain results in a T formation

R 

|

C-C-C

|

C

 An isopropyl group attached to an isobutyl group

R

|

C

|

C-C-C