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Structural isomers

Hello
I know this may sound like a silly question, but I'm still quite confused about how it is possible to know where to place the methyl group/ halogen atom etc around a compound? For example a question may be "draw the structural isomer of butan-3-ol" but I wouldn't know where to place the OH group! Could it go anywhere on the compund or does it has to be on a specific carbon atom?

*sorry if I confused you
Firstly, you cannot have butan-3-ol because then it would be butan-2-ol. Anyway, you just have to see how moving an alkyl or functional group would effect the name. For instance, butan-1-ol. The OH is on the first carbon, you can them move it to the second carbon to get butan-2-ol, however moving it to the third with still give 2-ol because its always the lowest number. Just remember to see that when you've moved it, if it effects the name and make sure the number is always the smallest it can be. Don't forget alkyl groups (eg. Methyl) sometimes count as the longest carbon chain!

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Reply 2
Original post by ravichauhan11
Firstly, you cannot have butan-3-ol because then it would be butan-2-ol. Anyway, you just have to see how moving an alkyl or functional group would effect the name. For instance, butan-1-ol. The OH is on the first carbon, you can them move it to the second carbon to get butan-2-ol, however moving it to the third with still give 2-ol because its always the lowest number. Just remember to see that when you've moved it, if it effects the name and make sure the number is always the smallest it can be. Don't forget alkyl groups (eg. Methyl) sometimes count as the longest carbon chain!

Posted from TSR Mobile


Thanks a lot, you really helped! :smile:

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