[lissydoll206]

Hi-

  I'm trying to work on a homework assignment. I have to draw out and name all of the constitutional isomers of Octane.  I looked at a table to see how many constitutional isomers there are for Octane, and there are 18, right?

  I've been working on it for awhile now, and I can only come up with 13.  Could someone please look over the names of the isomers that I have figured out to make sure I have them right, and give me a hint as to what the last 5 might be?

  Thanks- it is greatly appreciated.

Octane Constitutional Isomers

2-methyl-heptane
3-methyl-heptane
4-methyl-heptane
(2,2)-dimethyl-hexane
(2,3)-dimethyl-hexane
(2,4)-dimethyl-hexane
(2,5)-dimethyl-hexane
(3,3)-dimethyl-hexane
(3,4)-dimethyl-hexane
(2,2,3)-trimethyl-pentane
(2,3,4)-trimethyl-pentane
(2,3,3)-trimethyl-pentane
2-methyl-3-butyl-pentane

[lemonoman]

Try using ethyl constiutents.  Ethyl to hexanes...a methyl and an ethyl to pentanes, etc...

And think about propyl constituents too...do they exist in a C₈ structure?

Good luck  

[Mitch]

Search the forums. This has been discussed previously.