Diels–Alder Reaction: The [4+2] Cycloaddition Students Google at 2 AM

Master the Diels–Alder reaction with an interactive pericyclic scrubber: s‑cis diene requirement, endo rule, regioselectivity, and stereospecificity. Includes practice problems.

  • Reactants: Conjugated diene + dienophile (alkene/alkyne, often with EWG)
  • Mechanism: Concerted pericyclic (single step)
  • Key requirement: Diene must adopt s‑cis conformation
  • Stereochemistry: Stereospecific (cis on dienophile stays cis in product)
  • Common selectivity: Endo preference (rule of thumb)
  • Exam type: Predict the major product
  • Exam type: Stereochemistry
  • Exam type: Regiochemistry

Related Resources

All 194 Mechanisms — Aromatic & Pericyclic (High-Yield Orgo II) Mechanism Flashcards AI Reaction Predictor Ask the AI Tutor