Methods for finding Isomers

[jezza_113]

Howdy ya'll, just wondering if a chem wiz out there may be willing to share an effeicient method of finding isomers of organic molecules. The whole process is very overwhelming for me at the moment and I'm sure I'm not alone. Cheers in advance 

[Pandemonium]

arrange the carbons such that you get the maximal number of unique carbon backbone (and branching configurations)
move the functional groups around these new carbon backbones and check whether there are any unique isomers.
presto.

(easier said than done)

[cara.mel]

I'd also add to actually draw them out, rather then going 'butane has 2 isomers. I think. :/'

[jezza_113]

Thanks for the input. Much appreciated.

[bec]

Similar question, what rules are there for the placement of electroneg atoms like chlorine and fluorine?
We were taught that they always had to go on the end of the molecules, but I was just doing a prac exam and one of the solutions showed that there are 5 possible strucutral isomers for C3H6FCl...which would only be possible if the F and Cl were able to be bonded to the central carbon atom...

[cara.mel]

Similar question, what rules are there for the placement of electroneg atoms like chlorine and fluorine?
We were taught that they always had to go on the end of the molecules, but I was just doing a prac exam and one of the solutions showed that there are 5 possible strucutral isomers for C3H6FCl...which would only be possible if the F and Cl were able to be bonded to the central carbon atom...

They can be attached to any carbon atom
Like you can have both 1-chloropropane and 2-chloropropane etc (that question was in the 2007 exam)

[bec]

ok, that makes sense then. thanks!

[Mao]

only the carboxyl group [(=O)OH] occurs at the end, the rest can be wherever.

another thing you should watch out for is nitrogen, sometimes they can be the "link", like n-methyl ethylamine

[bec]

another thing you should watch out for is nitrogen, sometimes they can be the "link", like n-methyl ethylamine

sorry, what?

[Collin Li]

another thing you should watch out for is nitrogen, sometimes they can be the "link", like n-methyl ethylamine

sorry, what?

Don't worry about that. Not on the course.