Question

Can someone explain why we start numbering from the right and not from the left? http://gyazo.com/56171160325fe32181191183eb051e3b.png

Answer 1

there is left or right,rub this from ur mind

Answer 2

You start numbering at the end which will give the major substituent the lowest number, and if there are more than one substituent which are equal, then you start numbering at the end which gives the lowest total sum of their locations.

Answer 3

HOW COME 4-CHLORO..?? AND 5-METHYL...

CHECK THIS AGAIN.. YOU HAVE DONE THE NUMBERING WRONG ..WHEN YOU STARTED NUMBERING FROM THE LEFT SIDE..

REDO THE NUMBERING.. AND THEN SEE WHICH SIDE GIVES YOU LOWEST SUM..

Answer 4

You start naming from the side which gives the lowest sum OF THE PRIMARY SUBSTITUENT(s).

In other words, the lowest sum of the iodine and chlorine locations is the correct name:

3-chloro-1-iodo-4-methylpentane