Number in front of name

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Number in front of name

Postby Lyndon_Bui_3J » Wed Mar 01, 2017 3:21 pm

I understand 4-methyl-octane has the 4 in front because the substituent is attached to the 4th carbon, but how will we know which carbon the substituent is attached to? Will it always be shown?

Miya McLaughlin 2B
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Re: Number in front of name

Postby Miya McLaughlin 2B » Wed Mar 01, 2017 3:55 pm

The name will tell you where the substituent is located. In the name, the number before the substituent will indicate which carbon it is attached to. If you are instead given a picture, the substituent will be the line or series of lines protruding from one of the carbons in the chain. If you are asked to write the name from the picture, you can label the carbons yourself and essentially choose which carbon the substituent is attached too.

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Re: Number in front of name

Postby Chem_Mod » Wed Mar 01, 2017 4:19 pm

Miya isn't entirely correct. If you're given the structure and are asked to name the molecule, you must number the longest carbon chain such that the substituents have the lowest possible numbers. We will get to this and go over some rules in upcoming lectures.

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