試題詳解

19. Which of the following is least likely to undergo a smooth crossed Claisen condensation with methyl pentanoate?
(A) (CH₃)₃CCO₂CH₃
(B) PhCH₂CO₂CH₃
(C) PhCO₂CH₃
(D) HCO₂CH₃
(E) (CH₃O)₂CO