Ozonolysis: Alkene Cleavage and Workup Rules (Reductive vs Oxidative)

Ozonolysis cleaves alkenes into carbonyls. Learn the mechanism (ozonide) and how workup changes products: reductive gives aldehydes/ketones; oxidative gives acids. Includes practice.

• Overall transformation: Alkene → carbonyl fragments
• Core reagent: O3 (ozone)
• Key intermediate: Ozonide (via molozonide rearrangement)
• Reductive workup: DMS, Zn/AcOH → aldehydes/ketones
• Oxidative workup: H2O2 → aldehydes → carboxylic acids
• Exam type: Predict the major product
• Exam type: Choose conditions
• Exam type: Failure modes / distractors