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1-methyl 2-methyl 2,2-dimethyl 2,3-dimethyl
hexane
pentane pentane butane butane
Nomenclature of Alkenes & Alkynes-
1. Alkenes and alkynes withhydrocarbon chain lengths of four or greater require
a numbering scheme to the chain to designate the location of the multiple
bond.
2. The rules regarding this numbering scheme are:
a. The numbering system begins at the end of the molecule nearest the
location of the multiple bond.
b. The number in the name is assigned relative to the carbon in the chain
where the multiple bond begins.
c. A number is included for each multiple bondin the chain. The numbers are
separated by commas.
d. A dash connects the number locations to the hydrocarbon name.
e. Prefixes are added to the "ene" or "yne" final syllable when more than 1
multiple bondis present.
The first few prefixes for these are:
2 3 4 5 6 7 8
di tri tetr pent hex hept oct
3. For ring hydrocarbons (excluding aromatics such as benzene), attach "cyclo"
as the first syllable-
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