Nomenclature 10 pts?

Question

What is the names of CH3CHFCH3 and (CH3)3CCH2CHCLCH3

Also why is 1,3dimethylbutane not a correct name.

I got 2, fluro isoproyl and 4 cloro 1,1, dimythlpentane.

And my reason why is because the number is wrong it should be the first subsituent so it should be 2,4, dimethlybutane.

If my answer are right can you justify them. 10 points to who ever can correctly give an answer with the best reason why.

Answer 1

The first one is 2-fluoropropane.

The second one is 2-chloro-4,4-dimethylpentane.

. . . .CH3 . . . .Cl

CH3 - C - CH2 CH - CH3

. . . .CH3

The longest consecutive carbon chain is FIVE (thus pentane is our root word). You number the side chain starting with the end closest to a side chain. In this case, bith Cl and CH3 (2 of them) are on the second carbon from the end. But Cl gets the nod since it comes before methyl in the alphabet.

1,3-dimethylbutane is incorrect because the longest carbon chain is five carbons, not four. The correct name is 2-methylpentane.

  . . . . . . . . . . . . . .CH3

CH3 - CH2 - CH2 - CH - CH3

Answer 2

(a) 2-fluoropropane and 4-chloro-2,2-dimethylpentane**

(b) You can't have a "1-methyl" compound because this makes the longest chain (which gives you the root name of the compound) longer by one carbon.

"1,3-dimethylbutane" [CH3-CH2-CH2-CH(CH3)-CH3]  is correctly named 2-methylpentane.

** 4-chloro-2,2-dimethylpentane is correct as it gives lower numbers than 2-chloro-4,4-dimethylpentane.

Go to  http://old.iupac.org/nomenclature/index.... to use the free IUPAC naming programme to check out organic namings.