25. Which pair of structures represents the same compound? 
(A) I and II
(B) II and IV
(C) III and IV
(D) III and V
(E) IV and V

21. What is the major product of the following reaction?  (A) I (B) II (C) III (D) IV (E) V

22. Which of the following descriptions of the nucleoside uridine does NOT apply to the structure of the molecule? (A) The uracil base is directly bonded to the 1' position of ribofuranose in the α position. (B) The ribofuranose moiety is found in only the D configuration. (C) Nitrogen, at position 1 in the uracil base, is directly bonded to the ribofuranose moiety. (D) The 5' OH group is replaced with phosphate(s) in the nucleotide structure. (E) None of the above

23. Which sequence ranks the following aromatic rings of this compound in order of increasing reactivity in an electrophilic aromatic substitution reaction (slowest to fastest reacting)?  (A) 3 < 2 < 1 (B) 2 < 3 < 1 (C) 2 < 1 < 3 (D) 1 < 3 < 2 (E) 1 < 2 < 3

24. Which sequence ranks the indicated protons in order of increasing acidity?  (A) 3 < 2 < 1 (B) 2 < 3 < 1 (C) 2 < 1 < 3 (D) 1 < 3 < 2 (E) 1 < 2 < 3

26. What is the major product of the following reaction?  (A) I (B) II (C) III (D) IV (E) V

27. What is the major product of the following reaction? (A) I (B) II (C) III (D) IV (E) V

28. Which of the following is the strongest nucleophile? (A) NaOH (B) NaOMe (C) KOH (D) KOMe (E) KSMe

【已刪除】複選題29. Which would be the major product of the reaction shown? (A) I (B) II (C) III (D) IV (E) V (AB)送分

30. Provide the major product for the following reaction  ?(A) I (B) II (C) III (D) IV (E) V

31. Predict the major product for the following reaction.  (A) I (B) II (C) III (D) IV (E) I and II.