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

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

複選題59. Provide the reactants necessary to prepare the following alkene using the Wittig reaction. (A) ethanal and 2-bromopentane (B) propanal and 2-bromopentane (C) 2-pentanone and 1-bromopropane (D) 2-pentanone and 2-bromopropane (E) butanal and 2-bromopentane

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

61. Predict the major product of the following reaction sequence. (A) (B) (C) (D) (E) 

63. Predict the product of the following reaction. (A) I (B) II (C) III (D) IV (E) V

64. Predict the major product of the following reaction sequence. (A)(B)(C)(D)(E)

65. What is the relative reactivity of 2° vs 1° hydrogens in the free radical bromination of n-butane if the ratio of 1-bromobutane to 2-bromobutane formed is 7:93? (A) The 2° hydrogens are 20 times more reactive than the 1° ones. (B) The 2° hydrogens are 40 times more reactive than the 1° ones. (C) The 2° hydrogens are 60 times more reactive than the 1° ones. (D) The 2° hydrogens are 80 times more reactive than the 1° ones. (E) The 2° hydrogens are 100 times more reactive than the 1° ones.

66. Which sequence of reagents works best to convert 1-methyl-1-vinylcyclohexane to E-1-methyl-1-(prop-1-en-1-yl)cyclohexane? ? (A) 1. NaOCH3, CH3OH 2. NaNH2 3. Br2 4. H2 (excess), Pd/C (B) 1. Br2 2. NaNH2 3. NaNH2, then CH3Br 4. Na, NH3 (C) 1. BH3*THF 2. Br2 3. NaCN 4. Na, NH3 (D) 1. NaCN 2. HO- , H2O2 3. NaNH2, then CH3Br 4. Na, NH3 (E) 1. BH3*THF 2. Br2 3. NaNH2, then CH3Br 4. H2 (excess), Pd/C

67. How many of these reagents cause only syn additions to alkenes? HBr H2, Pd BH3 H2O2 CH3CO3H Br2 Hg(OAc) 2 (A) 1 (B) 2 (C) 3 (D) 4 (E) 5

68. The HOMO of (2E,4Z,6E)-octatriene undergo thermal cyclization using which process and which product? (HOMO orbital of pi-electrons of octatriene is given below, not showing the stereochemistry) (A) disrotatory and cis-product (B) conrotatory and cis-product (C) disrotatory and trans-product (D) conrotatory and trans-product (E) both disrotatory and conrotatory to give trans and cis product respectively