Chapter 16: Oxidation and Reduction Reactions

What is oxidation in organic chemistry?

Increase in C–O (or C–X) bonds OR decrease in C–H bonds

What is reduction in organic chemistry?

Increase in C–H bonds OR decrease in C–O bonds

What happens to the oxidation state of carbon during oxidation?

It increases as it loses electron density

What happens to the oxidation state of carbon during reduction?

It decreases as it gains electron density

What are the reagents for alkene hydrogenation?

What is the product?

What is the stereochemistry?

H₂, Pd/C (or Pt, Ni)

Alkane

Syn addition

What does H₂ + Pd/C do to an alkyne?

What does Lindlar catalyst do?

What does Na/NH₃(l) do?

Fully reduces to alkane

Reduces alkyne to cis-alkene

Reduces alkyne to trans-alkene

Carbonyl Reductions

What does NaBH₄ reduce?

What does LiAlH₄ reduce?

What type of reagent are NaBH₄ and LiAlH₄?

Aldehydes and ketones → alcohols

Aldehydes, ketones, esters, carboxylic acids → alcohols

Hydride donors (H⁻)

What happens when a primary alcohol is oxidized?

What happens when a secondary alcohol is oxidized?

Can tertiary alcohols be oxidized easily?

→ Aldehyde → Carboxylic acid (with strong oxidizer)

→ Ketone

No (no H on carbon with OH)

What is PCC used for?

What do strong oxidizers (like chromic acid) do?

Oxidizes primary alcohol → aldehyde (stops there)

Oxidize primary alcohol → carboxylic acid

Epoxidation

What reagent forms an epoxide from an alkene?

What is the stereochemistry of epoxidation?

Does epoxidation go through a carbocation?

Peroxyacid (e.g., mCPBA)

Stereospecific (retains alkene geometry)

No (concerted mechanism)

Dihydroxylation

What does OsO₄ do to an alkene?

What is the stereochemistry of OsO₄ addition?

Forms a vicinal diol

Syn addition

Oxidative cleavage

What reagent is used for ozonolysis?

What does ozonolysis do?

What products form from ozonolysis?

O₃

Breaks double bond → forms carbonyls

Aldehydes and/or ketones