Chapter 12: Alcohols from Carbonyl Compounds

Lecture Overview

Focus on oxidation and reduction chemistry of alcohols.
Transitioning from substitutions and eliminations to carbonyl chemistry.
Topics to cover include:
- Oxidation and reduction reactions of alcohols.
- Multi-step synthesis strategy.
- Introduction to the Grignard reaction.
Anticipated to complete the chapter by early next week.

Oxidation: Conversion of alcohol to a carbonyl group (aldehydes or ketones).
- Involves loss of hydrogens and formation of carbon-oxygen double bonds.
- Alcohol to aldehyde/ketone: Loss of two hydrogens (one from carbon, one from oxygen).
- Alcohol to carboxylic acid: Loss of two hydrogens, addition of OH group.
Reduction: Opposite of oxidation, adding hydrogen to convert carbonyl group back to alcohol.
- Aldehyde/ketone to alcohol: Hydrogen addition.
- Carboxylic acid to alcohol: Hydrogen addition.

Primary Alcohols:
- Use Pyridinium Chlorochromate (PCC).
- Converts primary alcohols to aldehydes.
- Structure includes chromium.
- Reactivity: Specific to primary alcohols.
Secondary Alcohols:
- Use Chromic Acid (H2CrO3).
- Oxidizes secondary alcohols to ketones.
- Ketones have two alkyl groups bonded to a carbonyl.
Tertiary Alcohols:
- No hydrogen on the carbon with OH group; not oxidized to carbonyl compounds.
- Strong oxidizing agents destroy tertiary alcohols to CO2.

Sodium Borohydride (NaBH4):
- Effective for reducing simple carbonyl compounds.
- Reduces aldehydes back to primary alcohols.
- Reduces ketones back to secondary alcohols.
- Safe storage of hydrogen gas but not efficient for energy storage.

Chromium reagents are hazardous; not used in research or labs by green chemists.
Future discussions will introduce additional reagents in carboxylic acids chapter.

End of Recording