4.3A NOMENCLATURE OF UNBRANCHED ALKYKL GROUPS
- Alkyl groups: -ane ⇒ -yl (alkane ⇒ alkyl)
Alkane Alkyl Group Abbreviation
CH 3 —H
Methane becomes
CH 3 —
Methyl Me–
CH 3 CH 2 —H
Ethane becomes
CH 3 CH 2 —
Ethyl Et–
CH 3 CH 2 CH 2 —H
Propane becomes
CH 3 CH 2 CH 2 —
Propyl Pr–
CH 3 CH 2 CH 2 CH 2 —H
Butane becomes
CH 3 CH 2 CH 2 CH 2 —
Butyl Bu–
4.3B NOMENCLATURE OF BRANCHED-CHAIN ALKANES
- Locate the longest continuous chain of carbon atoms; this chain determines the
parent name for the alkane.
CH 3 CH 2 CH 2 CH 2 CHCH 3
CH (^3)
CH 3 CH 2 CH 2 CH 2 CHCH 3
CH 2
CH (^3)
- Number the longest chain beginning with the end of the chain nearer the
substituent.
Substiuent
CH 3 CH 2 CH 2 CH 2 CH
CH 2
CH 3
7 6 5 4 3
2
1
CH 3
CH^63 CH^52 CH^42 CH^322 CHCH^13
Substiuent CH (^3)
- Use the numbers obtained by application of rule 2 to designate the location of
the substituent group.