Reaction Summary
Reagents
- Hydrogen cyanide,
Conditions
- Room temperature
Catalyst
- Trace
/ (source of nucleophile)
Chemical Equation
Equation
By-Products
- None
Observations
Observations
- No visible change (colourless liquid/solution throughout)
⚠️ 9701 Exam Notes / Pitfalls
Warning
- You must state the trace
/ : is a weak acid, so it provides too few nucleophiles on its own. - Mechanism:
attacks the carbonyl C ➔ alkoxide intermediate ➔ protonated by (regenerating ). - Chain extended by one carbon.
- Planar C=O can be attacked equally from either side ➔ racemic mixture (no optical activity) whenever the product has a chiral centre (all aldehydes except methanal).