Interpretation: The percentage compositions of the mixture of isomeric methylbutenes obtained from 2-bromo-2-methylbutane with potassium hydroxide and potassium tert-butoxide needs to be calculated.
Concept Introduction: In the dehydrogenation reaction of 2-bromo-2-methyl butane, mixture of products is formed only if the halogen is asymmetrically located on the carbon skeleton.
2-bromo-2-methyl butane results in the production of 2-methyl-2-butene and 2-methyl-1-butene on reaction with a strong base that is KOH. The elimination reaction is irreversible thus, the ratio of products formed are defined by the relative rates of the formation of two products.
The rate of the formation is determined by the relative free energies of the 2-transition states rather than the free energies of the products itself.
The product formed in higher yield is more substituted
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