What NEET Asks
- Direct naming of complex organic compounds with one or more functional groups.
- Identifying the principal functional group based on priority rules.
- Questions involving cyclic compounds or specific functional group suffixes.
Key Points
- Parent Chain: Select the longest continuous carbon chain containing the principal functional group.
- Numbering: Number the chain from the end that gives the principal functional group the lowest possible locant.
- Principal Functional Group: The functional group with the highest priority determines the suffix of the IUPAC name.
- Substituents: Other functional groups with lower priority are treated as substituents and named with prefixes.
- Alphabetical Order: When multiple substituents are present, they are listed alphabetically.
- Cyclic Compounds: If a functional group is directly attached to a ring, the ring is usually the parent. Specific suffixes like '-carboxylic acid' are used.
Must-Know Formula / Reaction
Functional Group Priority Order (Decreasing): Carboxylic acid > Sulfonic acid > Anhydride > Ester > Acyl halide > Amide > Nitrile > Aldehyde > Ketone > Alcohol > Thiol > Amine > Alkene > Alkyne > Ether > Halogen > Nitro > Alkyl
- Suffixes: -oic acid (COOH), -oate (COOR), -oic anhydride, -oyl halide, -amide (CONH2), -nitrile (CN), -al (CHO), -one (C=O), -ol (OH), -thiol (SH), -amine (NH2).
- Prefixes: carboxy-, sulfo-, alkoxycarbonyl-, haloformyl-, carbamoyl-, cyano-, formyl- or oxo-, oxo-, hydroxy-, mercapto-, amino-.
Common Mistakes
- Students often fail to correctly identify the principal functional group, leading to incorrect suffixes.
- Don't confuse the numbering of the parent chain with the longest carbon chain. The principal functional group must get the lowest possible number.
- Incorrectly applying prefixes for lower-priority functional groups or omitting them entirely.
Rapid Revision
Prioritize, number, name. The highest priority functional group dictates the suffix. Other groups become prefixes. Remember specific suffixes for cyclic compounds like -carboxylic acid. Practice with the priority order!