IUPAC Rules for Naming Organic Compounds

Overview

• IUPAC Naming System: Used to systematically name organic compounds by determining the structure of the molecule and applying standardized rules.
• Basic Components:
  • Parent Chain: Longest continuous carbon chain in the compound.
  • Suffix: Reflects the type of functional group(s).
  • Substituents: Groups attached to the parent chain.

Naming Alkanes

• Alkanes: Saturated hydrocarbons with single bonds.
• Straight Chain Alkane Names:
  • 1 Carbon: Methane
  • 2 Carbons: Ethane
  • 3 Carbons: Propane
  • ...
  • 12 Carbons: Dodecane
• Substituents: Named by replacing '-ane' with '-yl'.

Rules for Naming

1. Identify the Longest Carbon Chain: This is the parent chain.
2. Identify Substituents: Any groups attached to the parent chain.
3. Number the Parent Chain: Assign numbers to give substituents the lowest possible numbers.
4. Multiple Substituents: Indicate number and position using prefixes (di-, tri-, tetra-).
5. Alphabetical Order: List different substituents alphabetically, ignoring prefixes except "iso".
6. Tiebreakers: Choose the parent chain based on the number of side chains, lowest substituent numbers, etc.
7. Cyclic Compounds: Use "cyclo-" as a prefix.

Specific Compound Types

• Alkyl Halides: Halogen-treated as substituents with equal rank as alkyl groups.

  • Represented by: Fluoro- (F), Chloro- (Cl), Bromo- (Br), Iodo- (I)

• Alkenes and Alkynes: Unsaturated hydrocarbons with double (-ene) or triple (-yne) bonds.

  • Priority given to multiple bonds over substituents.
  • Double bonds take priority in numbering.

• Alcohols: Replace "-ane" with "-anol" and indicate the position of hydroxyl groups.

  • Priority of hydroxyls over alkyls and halogens.

• Ethers: Named using common names, with alkyl groups in alphabetical order.

• Aldehydes: Replace "-ane" with "-anal".

  • Priority of carbonyl group over others in numbering.

• Ketones: Replace "-ane" with "-anone".

  • Carbonyl group has naming priority.

• Carboxylic Acids: Longest chain including carboxyl (-COOH) determines naming.

  • Carboxyl group always at carbon #1.

• Esters: Named based on corresponding carboxylic acid, with "-oic acid" replaced by "-ate".

• Amines: Named like ethers with alkyl groups alphabetically ordered.

Functional Groups Summary

• Carboxylic Acids: Suffix is "-oic acid"
• Aldehydes: Suffix is "-al"
• Ketones: Suffix is "-one"
• Alcohols: Suffix is "-ol", Prefix is "hydroxy-"
• Amines: Suffix is "-amine", Prefix is "amino-"
• Ethers: Suffix is "-ether", Prefix is "alkoxy-"
• Halogens: Prefixes are "fluoro-", "chloro-", "bromo-", "iodo-"