Carbohydrates:
Resonance
occurs when a molecule shares all electrons equally, forming potentially half bonds from a combination of single and double
bonds. See Fig.1
Aromatic
contain one or more six-carbon rings characteristic of benzene.
-Benzene is a six-carbon
ring, which exhibits resonance, and is the base for many other molecules. See Fig. 2
Isomers
are molecules with the same atoms but different arrangements.
Aliphatic-
chained carbons
Naming
aliphatic carbohydrates:
Alkanes-
carbon chains with only single bonds
-Also known as “saturated”
-Suffix: “-ane”
Alkenes-
carbon chains with a double bond
-Suffix: “-ene”
Alkynes-
carbon chains with a triple bond
-Suffix: “-yne”
Prefixes:
meth-
1 C
eth-
2 C
prop-
3 C
but-
4 C
pent-
5 C
hex-
6 C
hept-
7 C
oct-
8 C
non-
9 C
dek-
10 C
Rules:
1)
Find the longest chain to be the parent chain that includes all (if any) double or triple bonds. This
will get the suffix (-ane, -ene, or -yne).
2)
Number the carbons so that the branches are off of the lowest possible numbers.
3)
Alphabetically, start naming the branches as such:
A 1
carbon chain (methyl) off of carbon 3 would be: 3-methyl
Two
2 carbon chains (ethyl) off of carbons 3 and 4 would be: 3,4-diethyl
Four
3 carbon chains (propyl) off of carbons 1 and 2 (2 off of Carbon 1 and 2 off of Carbon 2)
If propyl branches are connect at an end, put
-n-propyl. If connected at the second Carbon, put –isopropyl.
If there
are more than one branch per Carbon, repeat the number as many times as necessary, separating with commas
4)
Punctuate as follows:
number to number: 2,3
number to word: 1-methyl-2-diethyl
5)
Treat halogens as if they were branches, naming them as such:
A Chlorine
atom off of carbon 2 would be: 1-chloro
2 Bromine
atoms off of carbon 2 and 3 would be: 2,3-bromo
6)
If it is an alkene or alkyne, indicate which bond is a double or single as such: 3-ethyl-2-octene, which
indicates the fourth bond is a double bond.
7)
If the molecule is cyclic, include the prefix “cyclo”, unless it is hexane. In this case,
replace “cyclohexane” for benzene.
