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

46. Which of the following statement(s) is(are) true for the following reaction? I. This reaction shows high (Z)-alkene selectivity. II. When n-BuLi and Et2O were used as the base and solvent, the selectivity decreases. III. This reaction is under kinetic-controlled. (A) I (B) II (C) III (D) I and III (E) All of the above

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

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

49. Which of the following synthetic procedures would be employed most effectively to transform ethanol into ethyl propyl ether? (A) 1. Ethanol, HBr 2. Mg, ether, then H3O 3. NaH, then CH3CH2Br (B) 1. Ethanol, HBr 2. Mg, ether, then HCHO, then H3O 3. NaH, then CH3CH2Br (C) 1. Ethanol 2. CH3CH2CH2OH 3. H2SO4, 140 °C (D) 1. Ethanol, NaH 2. HCHO, then H3O 3. HBr, then Mg, ether, then CH3CH2CH2Br (E) 1. Ethanol 2. H2SO4, 180 °C 3. CH3CH2CH2Br

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

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

53. What is the major product of the following reaction? (A)  (B)  (C) (D)  (E)

54. Which reagent is most suitable for the following transformation? (A) CuF (B) F-TEDA-BF4 (C) AgSbF6 (D) HBF4 (E) n-Bu4NF

55. What is the major product of the following reaction? (A) (B) (C) (D) (E) None of the above

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