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

20. What is the major product for the reaction sequence below. (A) (B) (C) (D) (E)

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

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

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