49. Predict the major product for the following Claisen rearrangement. 
(A) I
(B) II
(C) III
(D) IV
(E) None of the above

45. The 1 H NMR spectrum of which of the compounds below, all of formula C7H12O2, would consist of three singlets only? (A) I (B) II (C) III (D) IV (E) V

46. Arrange the following in order of increasing basicity: aniline, p-nitroaniline, p-toluidine, and p-methoxyaniline. (A) p-toluidine < p-methoxyaniline < aniline < p-nitroaniline (B) p-nitroaniline < p-toluidine < aniline < p-methoxyaniline (C) p-nitroaniline < aniline < p-toluidine < p-methoxyaniline (D) p-methoxyaniline < p-nitroaniline < p-toluidine < aniline (E) None of the above 

47. What is the thermodynamic product of the sulfonation of naphthalene?

48. For the reaction shown, which of the compounds listed below would be the expected major, and final, organic product?  (A) I (B) II (C) III (D) IV (E) V

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

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 → 

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