In the dehydrohalogenation of 2-bromo-2-methylbutane, utilizing a sterically bulky base such as pota — Reaction Mechanism Chemistry Question
Question
In the dehydrohalogenation of 2-bromo-2-methylbutane, utilizing a sterically bulky base such as potassium tert-butoxide ($K^+\,{}^-O-t-Bu$), which specific alkene is generated as the major product?
💡 Solution & Explanation
While standard $E2$ eliminations generally follow Saytzeff's rule to produce the most thermodynamically stable (highly substituted) alkene, sterically bulky bases like $tert-butoxide$ cannot easily access hindered internal $\beta$ -protons. Instead, they abstract the more exposed terminal primary protons. This dictates a kinetically controlled pathway, resulting in Hofmann's rule and producing the less substituted 2-methyl-1-butene as the major product.