25. Predict the major product for the following reaction sequence. 
(A) I
(B) II
(C) III
(D) IV
(E) V

21. Provide the structure of the major organic product in the reaction below. (A) I (B) II (C) III (D) IV (E) V

22. Which reaction condition could NOT give the indicated product in the following scheme? (A) POCl3, pyridine (B) KMnO4, H3O+ (C) CH3CH2OH, H+ (D) Na+ －OEt, then CH3MgBr (E) H3O+ , heat

23. What is the IUPAC name for the following compound? (A) (R)-2-bromo-2-methylcyclobutanone (B) (S)-2-bromo-2-methylcyclobutanone (C) (R)-2-methyl-2-bromocyclobutanone (D) (S)-1-bromo-1-methyl-2-cyclobutanone (E) (R)-1-bromo-1-methyl-2-cyclobutanone

24. The exo-product is the minor product during the 4+2 reaction. Which is the exo-product? (A) (B) (C) (D) (E)

26. Which of these alkyl halides cannot be used to prepare amines using Gabriel synthesis? (A) 1-bromopentane (B) 1-bromo-3-methylbutane (C) 2-bromo-3-methylpentane (D) 1-bromo-2,3-dimethylbutane (E) 2-bromo-2,3-dimethylbutane

27. Predict the major product for the following reaction sequence. (A) (B) (C) (D) (E)

28. Identify which of the structures below are meso structures (A) I (B) I and III (C) I, III and V (D) I, III and IV (E) II and V

29. Which of the following statements regarding these three compounds is incorrect? (A) I can be converted to III using methanol and catalytic amounts of H2SO4. (B) I can be converted to II using acetic acid and catalytic amounts of H2SO4. (C) II can be produced from I by reaction with acetic anhydride. (D) II and I both will react with sodium bicarbonate to evolve carbon dioxide. (E) II and III are both esters.

30. The acetoacetic ester synthesis, shown below, can be used to prepare 5-methyl-2-hexanone. Which one of the following alkyl bromides would be used in the synthesis? (A) (CH3)2CHBr (B) (CH3)2CHCH2Br (C) (CH3)2CHCH2CH2Br (D) CH3CH2CHBrCH3 (E) (CH3)2CBrCH3

31. Choose the major product of the following reaction. (A) (B) (C)  (D) (E)