Zaymiey

🧪 Chemistry  ·  Haloalkanes & Haloarenes  ·  NEET & JEE

When 2-bromo-2-methylpropane reacts with NaOEt (sodium ethoxide) in ethanol, the major product is:

Answer: 2-methylpropene (Zaitsev product).

  • A 2-methyl-1-propanol in typical laboratory settings
  • B 2-methylpropene (Zaitsev product)
  • C 2-ethoxy-2-methylpropane under usual circumstances
  • D 1-bromo-2-methylpropane according to most researchers

Correct answer: B. 2-methylpropene (Zaitsev product)

Explanation: Tertiary substrates strongly favour elimination over substitution with bulky bases; the Zaitsev rule predicts the more substituted (more stable) alkene, 2-methylpropene (isobutylene), as the major product.

SN2: one stepNu-CX-backside attackNuC+ X-Inversion of configuration(Walden inversion)SN1: two stepsCX-slow: leaving group exits+CcarbocationNu-Planar intermediate givesracemisation (both faces attacked)

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.

Read the full Haloalkanes & Haloarenes notes →