CH 3 CH CHCH 3
CH 3 CH 3
2,3-Dimethylbutane
CH 3 CHCHCHCH 3
CH 3
CH 3
CH 3
Trimethyl
CH 3 CCHCCH 3
CH 3 CH 3
CH 3 CH 3
2,3,4- pentane 2,2,4,4-Tetramethylpentane
- When two chains of equal length compete for selection as the parent chain, choose
the chain with the greater number of substituents.
CH 3 CH 2 CH CH CH CH CH 3
CH 3 CH 3 CH 3
Trimethyl-4-
CH 2
2,3,5- propylheptane
CH 2
CH 3
7 6 5 4 3 2 1
(four substituents)
- When branching first occurs at an equal distance from either end of the longest
chain, choose the name that gives the lower number at the first point of
difference.
H 3 CCHCH 2 CH CH CH 3
CH 3 CH 3 CH 3
Trimethyl
Trimethyl
2,3,5- hexane
6 5 4 3 2 1
(not 2,4,5- hexane)
4.3C NOMENCLATURE OF BRANCHED ALKYL GROUPS
- Three-Carbon Groups
CH 3 CH 2 CH 3
CH 3 CH 2 CH 2
H 3 CCH
CH 3
Propyl group
Propane 1-Methylethyl or isopropyl group
