Naming organic compounds can be a bit daunting, as there are a lot of rules and the names just get longer as the molecules get more complex, even if it is something familiar to you. Do you recognise the following names?
(10R,13R)-10,13-dimethyl-17-(6-methylheptan-2-yl)-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol

Cholesterol
(5R)-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one

Ascorbic acid, or vitamin C
(5α,6α)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol diacetate

Heroin
Once you get the hang of it, naming organic compounds is really very easy, and I will demonstrate with the following molecule:

This one
First thing to do is find the longest carbon chain.

Longest carbon chain has 7 carbons
Then identify what functional groups, (if any) are present:

We have one methyl group and one chloro group
Now we number the carbons on the chain, so that the largest number of substituents have the lowest number:

This way the chloro is number 2 and the methyl is number 5. If I’d numbered it the other way, the methyl would be 3 and the chloro 6.
Now we put it all together remembering that we order the substituents alphabetically, a hyphen goes between a number and a letter, a comma goes between two numbers and there shouldn’t be any spaces, (except when the functional group requires it).
So… that gives us: 2-chloro-5-methylheptane!
Easy!
Here are some links to some practice questions:
http://www.chembio.uoguelph.ca/educmat/chm19104/nomenclature/quizes.html
http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Questions/Nomencl/nomencl.htm
The order of precedence of functional groups can be found here
Hey Emma,
Its cal, just wondering with the last question from quiz one, there was a cycloalkane in triangle form, I couldn’t figure out what it was?
thanks
A three membered cycloalkane is cyclopropane. The one you mentioned is called 2-ethyl-1,1-dimethylcyclopropane.