Acyclic Hydrocarbons
Rule A-1. Saturated Unbranched-chain Compounds and
Univalent Radicals
1.1 - The first four saturated unbranched acyclic hydrocarbons are called methane,
ethane, propane and butane. Names of the higher members of this series consist of a
numerical term, followed by "-ane" with elision of terminal "a" from the numerical
term. Examples of these names are shown in the table below. The generic name of
saturated acyclic hydrocarbons (branched or unbranched) is "alkane".
Examples of names:
(n = total number of carbon atoms)
n
n
1 Methane
22 Docosane
2 Ethane
23 Tricosane
3 Propane
24 Tetracosane
4 Butane
25 Pentacosane
5 Pentane
26 Hexacosane
6 Hexane
27 Heptacosane
7 Heptane
28 Octacosane
8 Octane
29 Nonacosane
9 Nonane
30 Triacontane
10 Decane
31 Hentriacontane
11 Undecane 32 Dotriacontane
12 Dodecane 33 Tritriacontane
13 Tridecane 40 Tetracontane
14 Tetradecane 50 Pentacontane
15 Pentadecane 60 Hexacontane
16 Hexadecane 70 Heptacontane
17 Heptadecane 80 Octacontane
18 Octadecane 90 Nonacontane
19 Nonadecane 100 Hectane
132 Dotriacontahectane
20 Icosane
21 Henicosane
Reference: http://www.acdlabs.com/iupac/nomenclature/79/r79_34.htm
Organic Chemistry
Carbon in an organic molecule has an s1p3 valence:
Since there are four half-full orbitals, organic carbon needs four bonds (4 single bonds, 2 double
bonds, 2 single bonds and 1 double bond, or 1 single bond and one triple bond).
Hydrocarbons are organic compounds containing only C and H
Alkanes have only single bonds (CnH2n+2), and their names end in “-ane”
methane
CH4
ethane
C2H6
propane
C3H8
butane
C4H10
pentane
C5H12
hexane
C6H14
heptane
C7H16
octane
C8H18
nonane
C9H20
decane
C10H22
When an Alkane becomes a functional Group, it loses an H, its name loses the “-ane”
suffix, and it now ends in “-yl”.
Alkenes have at least one double bond, and their names end in “-ene”.
Alkynes have at least one triple bond, and their names end in “-yne”.
Naming Alkanes with functional groups:
 Consider the longest chain of carbons as the main parent
 Find and maintain the lowest total numbering system (left to right or right to
left)
 Name the functional groups in alphabetical order.
 With multiples of the same group, use “di-“, “tri-“, “tetra-“, “penta-“, “hexa-“,
“hepta-“, “octa-“, “nona-“, “deca-“.
 Put a dash between letters and numbers and a comma between numbers
Naming alkenes/alkynes with functional groups:
 A position number is given to the carbon on which the double/triple bond
begins
 Begin at the end that will make this position number the lowest
 This position number is always placed just before the name of the main parent
chain(the longest chain containing the double/triple bond)
 If the molecule has more than one double/triple bond, the “-ene”/”-yne”
ending must be preceded by a prefix indicating the number of double/triple
bonds

Name the functional groups as for alkanes
Examples:
2,4-diethyl-3-methylpentane
4,6-dimethyl-5-propyl-2,3,5-nonatriene
Naming Cyclic compounds:
 the cyclic compound is considered to be the main parent chain
 the functional groups are named in alphabetical order and numbered around
the compound with the lowest possible numbering system
Example:
benzene
toluene
7-ethyl-2,3-dimethylnaphthalene
phenol
Name:__________________ Period: _______________
Hydrocarbon
Aliphatic
Saturated
Base
Straight
Chain
Alkane
C1
meth
C2
eth
C3
prop
C4
but
butane
C5
pent
pentane
C6
hex
C7
hept
C8
oct
C9
non
nonane
C10
dec
decane
Unsaturated
Formula
Alkene
Akyne
CnH2n+2
Saturated
Cyclic
Compound
Functional
Group
CnH2n+1
methane
C2H6
ethyl
C2H5-
ethyne
propene
cyclobutane
pentyl
C5H111-hexene
heptyl
C7H15-
1-heptyne
C8H18
1-octene
1-nonyne
cyclononane
Decyl
C10H21-
Polymers:
Addition Polymers
Condensation Polymers
Carbohydrates:
Monosaccharides – glucose, fructose
Disaccharides – sucrose
Polysaccharides – starch, cellulose
Amino Acids
Peptides
Proteins
Enzymes/Co-enzymes
Lipids
Triglycerides
Phospholipids
Waxes
Nucleic Acids
DNA
RNA