Answer: Zaitsev rule: more substituted alkene (2-methyl-2-butene) is major.
- A Hofmann rule: less substituted alkene is major
- B Zaitsev rule: more substituted alkene (2-methyl-2-butene) is major
- C Exactly equal amounts of both possible alkene isomers form
- D No elimination occurs at all under these solvolysis conditions
Correct answer: B. Zaitsev rule: more substituted alkene (2-methyl-2-butene) is major
Explanation: With a non-bulky base (EtOH) and a tertiary substrate, elimination predominates and the Zaitsev rule applies: 2-methyl-2-butene (trisubstituted) is formed preferentially over 2-methyl-1-butene (disubstituted).
SN2 proceeds in a single step with backside attack and inversion of configuration, while SN1 forms a planar carbocation intermediate first, leading to racemisation.
Concept context
Study carbon-halogen compounds: how they are made, how they react via SN1/SN2 and elimination, their stereochemistry, and their environmental impact.