Alcohols_

• Functional Groups:

  • Alcohol: Contains a hydroxyl group (-OH).

  • Phenol: Contains a hydroxyl group bonded to a benzene ring.

Alcohols

• Alcohols are organic compounds that contain one or more hydroxyl (-OH) functional groups.

Examples of Alcohols

• General formula: R-OH

• Common Examples:

  • Methanol (CH₃OH): Simplest alcohol.

  • Phenol (C₆H₅OH): Contains a hydroxyl group and is bonded to a benzene ring.

Naming Alcohols

Basic Naming Steps

1. Identify and name the longest continuous carbon chain that contains the hydroxyl group.

2. Modify the alkane name by dropping the final 'e' and adding the suffix -ol.

3. Number the carbon chain starting from the end closest to the hydroxyl group.

4. Identify and label the positions of any additional substituents in alphabetical order.

IUPAC and Common Naming Examples

• In the IUPAC naming system, replace the final 'e' with 'ol'.

• For common names: use the name of the alkyl group followed by "alcohol".

  • Methane → Methanol (Methyl Alcohol)

  • Ethane → Ethanol (Ethyl Alcohol)

Alcohols with Multiple Hydroxyl Groups

• Alcohols may have multiple hydroxyl groups:

  • Diol: Alcohol with two hydroxyl groups.

  • Triol: Alcohol with three hydroxyl groups.

Naming Cyclic Alcohols

• A cyclic alcohol is named as a cycloalkanol:

  • Number the ring starting from carbon 1, which is the carbon with the hydroxyl group.

  • If there are no substituents, numbering is unnecessary.

Naming Phenols

• Phenols: Hydroxyl group bonded to a benzene ring.

• When more than one substituent is present, number the ring starting at carbon 1 where the hydroxyl group is attached.

• Common names utilize ortho, meta, and para nomenclature for substituent positioning.

• Cresols refer to methylphenols.

Problem-Solving Steps for Naming Compounds

For Alcohols

1. Analyze the problem: Identify the longest chain, position of -OH, and additional substituents.

2. Replace 'e' in the alkane name with 'ol'.

3. Number the chain starting nearest to the hydroxyl group and label substituents.

• Example identification for IUPAC: 5-methyl-2-hexanol.

Practical Examples

• Analyze Example A: Five carbon chain with a hydroxyl group and a methyl group to find the IUPAC name.

• Phenol Names: Identify as an aromatic alcohol based on its structure.

Metabolism of Alcohols

Ethanol Metabolism

• Ethanol is processed in the body:

  • Converted via alcohol dehydrogenase (ADH) to acetaldehyde (toxic).

  • Further metabolized to acetate.

Methanol Metabolism

• Methanol is metabolized by ADH into formaldehyde and then to formic acid, which is also toxic.

• Competitive inhibitors like Fomepizole or ethanol can prevent methanol poisoning.

Uses of Alcohols

Ethanol (Ethyl Alcohol)

• Known historically for its intoxicating effects.

• Produced through fermentation processes.

• Utilized as a solvent in various products such as perfumes and medicinal tinctures.

1,2-Ethanediol (Ethylene Glycol)

• Commonly used as an antifreeze.

• Serves as a solvent for paints and production of synthetic fibers.

• Highly toxic, metabolized into oxalic acid, leading to severe health risks if ingested.