55. Which of the following will result in removal of a benzyl ester protecting group?
(A) acid hydrolysis only
(B) decarbonylation only
(C) catalytic hydrogenation only
(D) both acid hydrolysis and decarbonylation
(E) both catalytic hydrogenation and acid hydrolysis

51. Which of the following reagents can be used to cleave a tert-butoxycarbonyl (Boc) protecting group from a peptide? (A) H2/Pd (B) CF3CO2H (C) Na2CO3, H2O (D) LiAlH4 (E) None of the above

52. The reaction shown below would be expected to produce as major products which of the following compounds?(A)+ enantiomer(B)  + enantiomer (C)  + enantiomer (D)  + enantiomer (E)  + enantiomer

53. What is the best method for the preparation of m-dibromobenzene from benzene? (A) 1). HNO3/H2SO4; 2). Sn/HCl; 3). NaNO2/HCl, 0°C; 4). Br2/FeBr3, twice. (B) 1). HNO3/H2SO4; 2). Sn/HCl; 3). NaNO2/HCl, 0°C; 4). Br2/FeBr3; 5). H3PO2. (C) 1). HNO3/H2SO4; 2). Sn/HCl; 3). NaNO2/HCl, 0°C; 4). H3PO2; 5). Br2/FeBr3, twice. (D) 1). HNO3/H2SO4; 2). Br2/FeBr3; 3). Sn/HCl; 4). NaNO2/HCl, 0°C; 5). CuBr. (E) Br2/FeBr3, twice.

54. Which is the best method for the synthesis of tert-butyl methyl ether? (A) CH3ONa + (CH3)3CBr → (B) (CH3)3CONa + CH3I → (C) CH3OH + (CH3)3COH + H2SO4 at 140°C → (D) (CH3)3CONa + CH3OCH3 →(E) CH3ONa + (CH3)3COH → 

56. Which of the following ketones will give a positive iodoform test? (A) 3-heptanone (B) 3-hexanone (C) cyclohexanone (D) 2-pentanone (E) 2-methyl-3-hexanone

57. Which of the following compounds will display a singlet, a triplet and a quartet in the 1 H NMR spectrum? (A) 1-chloro-2,2-dimethylbutane (B) 3-chloro-3-methylpentane (C) 3-chloropentane (D) 2-chloro-4-methylpentane (E) 3-chloro-2-methylpentane

58. Examining the infrared spectrum of a compound allows us to: (A) determine the types of functional groups present in the compound (B) determine the carbon-hydrogen framework of the compound (C) determine the molecular weight of the compound (D) determine the nature of the conjugated pi electron system in the compound (E) None of the above is correct

59. Which of these is the least reactive type of organometallic compound? (A) RK (B) R2Hg (C) RLi (D) R2Zn (E) R3Al

60. Which one of the following compounds will have the lowest wavenumber for carbonyl absorption? (A) I (B) II (C) III (D) IV (E) V  

【單選題】每題 2 分，共計 40 分，答錯 1 題倒扣 0.5 分，倒扣至本大題零分為止，未作答，不給分亦不扣分。61. A student measured the optical activity of an unknown sugar at two different concentrations. The results of his measurements are shown below. Given that the sample cell had a path length of 10.0 cm, calculate the specific rotation for the unknown sugar.concentration                               observed rotation2.00 g sugar in 10.0 mL water              +159.1°  5.00 g sugar in 10.0 mL water              +127.8° (A) -10.5° (B) +25.6° (C) +79.5° (D) -104.5° (E) +256.2°