Chapter 8, Problem 8.47P

Interpretation Introduction

Interpretation: The reason as to why in the elimination of $\text{HBr}$ from $2$-bromobutane with sodium ethoxide as base, but-$2$-ene constitutes $81\%$ of the alkene products, but with potassium tert-butoxide, but-$2$-ene constitutes only $67\%$ of the products is to be explained.

Concept introduction: In $\text{E2}$ elimination reactions, generally a strong, negatively charged base is involved. According to Zaitsev rule the more alkylated alkene is the major product.