Naming Alcohols

Introduction to Alcohols

• Alcohols contain an OH (hydroxyl) group as their functional group.
• Represented as R-OH where R is the rest of the molecule.
• Alcohol is a high priority functional group; therefore, "ol" is added as a suffix.

Naming Straight Chain Alcohols

1. Identify the Parent Chain
   • Highlight the longest carbon chain where the OH group gets the lowest number.
2. Example
   • Five carbons = "pent"
   • Single bonds = "ane"
   • Alcohol on carbon 2 = "2-ol"
   • Name: 2-pentanol (drop the 'e' from "ane")

Naming Alcohols with Substituents

• Substituents are prefixes; alcohol is always the suffix.

1. Example: tert-butyl alcohol using IUPAC
   • Longest chain of three carbons = "prop"
   • Single bonds = "ane"
   • Alcohol on carbon 2 = "2-ol"
   • Methyl group on carbon 2 = "2-methyl"
   • Name: 2-methyl-2-propanol

Naming Cyclic Alcohols

• Rules are similar to straight chains but include cycles.

1. Example
   • Five carbons in a ring = "pent"
   • Add "cyclo" prefix due to the ring structure.
   • Alcohol on the only group = implied "1-ol"
   • Name: cyclopentanol

Diols

• Compounds with two OH groups.

1. Example
   • Six carbons in a ring = "hex"
   • Add "cyclo"
   • OH groups on carbons 1 and 2 = "1,2"
   • Include "di" to indicate two alcohols
   • Name: 1,2-cyclohexanediol (don't drop 'e' here)

Alcohols with Pi Bonds

• Prioritize alcohol over pi bonds.

1. Example
   • Five carbons = "pent"
   • Pi bond on carbon 3 = "3-ene"
   • OH on carbon 2 = "2-ol"
   • Name: 3-pentene-2-ol

Naming Bicyclic Compounds with Alcohols

• Follow rules for bicyclic systems.

1. Example
   • Start numbering at bridgehead closest to OH.
   • Seven carbons in chain = "hept"
   • Bicyclo prefix with [2.2.1] for unique carbon counts in rings.
   • Bromine = "5-bromo"
   • OH on carbon 2 = "2-ol"
   • Name: 5-bromobicyclo[2.2.1]heptane-2-ol

Tips

• Use puzzle pieces as a checklist for complex names.
• Follow sequence: prefix, first name, last name, suffix.