A bulky base in E2 reactions tends to favor which product?

• A. Zaitsev product (more substituted)
• B. Hofmann product (less substituted)
• C. No reaction
• D. Rearranged product

Answer: (B)

Bulky bases steer E2 eliminations toward the Hofmann product because sterics dominate the deprotonation step. In an E2, the base removes a β-hydrogen at the same time the leaving group leaves, and the hydrogen must be anti to the leaving group. A bulky base can access only the less hindered β–hydrogen, so it preferentially abstracts that one. Deprotonating the less substituted β-carbon leads to the less substituted alkene—the Hofmann product—even though a more substituted (Zaitsev) alkene would be thermodynamically favored with smaller bases.

The anti-periplanar requirement means only certain hydrogens are truly accessible, so the base’s size further biases which accessible hydrogen is removed. Rearranged products don’t occur in E2 (no carbocation intermediate to rearrange), and no reaction is not the general outcome under typical E2 conditions with a strong bulky base.