Hydrobromination
Protonation of propene favours the secondary carbocation over a primary one. Bromide then forms the C-Br bond at the central carbon.
- Reagents
- HBr
- Conditions
- Polar addition without radical initiators
- Reaction class
- Hydrobromination
- Equation
- CH3CH=CH2 + HBr -> CH3CHBrCH3
Overview
Protonation of propene favours the secondary carbocation over a primary one. Bromide then forms the C-Br bond at the central carbon.
Transformation
- Equation
- CH3CH=CH2 + HBr -> CH3CHBrCH3
- Reactants
- Propene + Hydrogen bromide
- Products
- 2-Bromopropane
- Reagents
- HBr
- Environment
- Polar addition without radical initiators
- Reaction class
- Hydrobromination
- Mechanism
- electrophilic addition through a carbocation
- Evidence level
- source-backed molecular example
Scope and limitations
- Scope
- Unsymmetrical alkene giving the Markovnikov addition product.
- Limitations
- Peroxide-initiated radical HBr addition follows different regiochemistry; it is outside this route.
Related reactions
- Hydration: Propene → Propan-2-ol
Propene gives propan-2-ol through hydration.
- Hydrolysis: 2-Bromopropane → Propan-2-ol
Replacing the carbon-bromine bond with carbon-oxygen bonding produces propan-2-ol. Its central carbon remains secondary, explaining its subsequent oxidation to propanone.
References
- Organic Chemistry: Orientation of Electrophilic Additions: Markovnikov’s RuleJohn McMurry · OpenStax Organic Chemistry · 2023
Checked 2026-09-16. Supports the reaction pattern and mechanistic explanation; named examples apply that scope to existing molecular records without claimed experimental yields.