試題詳解

39. Reactions of a series of substituted pyridines with BFs shows the order of Lewis basicity: Pyridine ＞2-methylpyridine ＞ 2,6-dimethylpyridine＞2-t-butylpyridine. Which of the folowing effects induces this order?
(A) 1-strain
(B) B-strain
(C) F-strain
(D) inductive effect
(E) leveling effect