## Finding the Main chain

Jose Avelar
Posts: 10
Joined: Fri Sep 25, 2015 3:00 am

### Finding the Main chain

When counting the carbons for determining what the longest chain is, does it matter which Carbon you start with in determining the longest chain?

Ronald Yang 2F
Posts: 86
Joined: Fri Sep 25, 2015 3:00 am

### Re: Finding the Main chain

Technically yes, since depending on which carbon you start from determines how long it would be. For example, you would want to start on a carbon that is preferably at the "end" of a chain, meaning that you would start counting from a primary carbon (carbon attached to only one carbon).

Srivinay_Irrinki
Posts: 20
Joined: Fri Sep 25, 2015 3:00 am

### Re: Finding the Main chain

Yes, when determening the main chain, it does matter which carbon you start with. To expand on Ronald's example, consider a molecule that is seven carbons long if you go directly from left to right, but has a branch of 3 carbons on the 5th carbon. In this case, the chain starting with the branch and stretching to the left will be the main chain as it contains 8 carbons. This is why the length of the main chain is dependent on which carbon you start with.