Catalytic Hydrogenation: Syn Addition on a Metal Surface

Catalytic hydrogenation reduces alkenes by syn addition of H2 on a metal surface. Learn the stereochemical outcomes, chemoselectivity basics, and exam-style shortcuts.

• Overall transformation: Alkene → alkane (reduction)
• Reagents: H2 with Pd/C, Pt, or Ni (varies by context)
• Stereochemistry: Syn addition (both H add from same face)
• Key concept: Adsorption on metal surface controls stereochemistry
• Common exam angle: Stereochemical outcome in rings or substituted alkenes
• Exam type: Predict the major product
• Exam type: Stereochemistry
• Exam type: Failure modes / distractors