Quick question: Hydrocarbon nomenclature

[kathyt.25]

I just have a quick question about hydrocarbon nomenclature:

When picking the "parent chain", I know that you're supposed to pick the one with the longest carbon chain... does the parent chain always have to have the double/triple bonds? Or can the double/triple bonds be located in a sidechain?

Also, when prioritizing alkyl groups, what has a higher priority - methyl, ethyl, propyl, etc. Or do you just prioritize these straight chain alkyl side groups by alphabetical order?

 

[ace123]

From what I remember of organic nomenclature the parent must always contain the double or triple. You cannot put as a side-chain. As for alkyl groups you just list them alphabetically.

 

[Blueshift5]

Hi there,

In hydrocarbon nomenclature, the parent chain is always the longest carbon chain in the molecule. This chain does not necessarily have to have the double or triple bonds, as these can be located in a sidechain. However, if the parent chain does contain a double or triple bond, it must be numbered in a way that gives the lowest possible number to the first multiple bond or functional group encountered.

When prioritizing alkyl groups, the higher priority is given to the group that appears first in alphabetical order. For example, ethyl would have a higher priority than propyl. However, if there are multiple identical groups, then the number of these groups is used to determine priority. For example, if there are two ethyl groups, they would be given a higher priority than one propyl group.

I hope this helps clarify your questions about hydrocarbon nomenclature. Let me know if you have any further questions.