BRAINCAKEAsymmetrical Alkenes
Asymmetrical alkenes react with concentrated sulfuric acid, and then water, to give a major and a minor alcohol. The rule is the same as with HBr: the major product forms via the more stable carbocation (tertiary > secondary > primary).
Propene. The δ+ H of H2SO4 can add to either carbon of the C=C:
• H to carbon 1 gives the secondary carbocation CH3CH+CH3. HSO4– bonds to carbon 2, so the major hydrogensulfate is CH3CH(OSO2OH)CH3, with the OSO2OH group on carbon 2.
• H to carbon 2 gives the less stable primary carbocation and the minor product CH3CH2CH2OSO2OH.
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Key terms in this lesson
- carbocation
- A positively charged carbon atom formed as a reactive intermediate when a bond breaks heterolytically.
More in Alkenes
- Reaction with Hydrogen Halides
- Asymmetrical Alkenes
- Reaction of Alkenes with Halogens
- Reaction with COncnetrated Sulfuric Acid
- Reaction with Water
- Addition Polymers
- Identifying the Repeating Group
- Identifying the Monomer
All 23 lessons in Alkenes · All AQA AS-level Chemistry topics