Now that you have the basics of naming, here are some tips on prioritization rules (i.e. giving functional groups priority or the lowest position number).
- Double bond “-enes” have priority over triple bond “-ynes”.
- Triple bond -ynes get priority over over phenyl.
- Halides/halogens have no special priority over alkyl groups.
- In general, you can expect any functional group containing an oxygen will have priority over functional groups without the oxygen.
- Alcohol has priority over alkyl, amines, halides, ethers, phenyl, and thiols.
- Thiols -SH get priority over alkyl and halides.
- If both thiols and alcohols are present, then alcohol gets priority.
- Aldehyde gets priority over double bond -enes and alcohol.
- Carboxyl group gets priority over aldehydes.
- Ketones get priority over -enes, phenyls, and alcohols.
- Carboxylic acids are highest priority and are terminal; there can only be a maximum of two carboxylic acids. Carboxylic acids get priority over alcohols, amines, ketones and aldehydes.
- Non carboxylic acid carbonyls (acting as substituents) get the “oxo” name.
- Esters have priority over carboxylic acids and the nitrile group.
- Groups with oxygen have priority over amines.
- Amides get priority over amines.
