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

62. Choose 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.

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

複選題69. Assuming kinetic conditions, provide a structure for the major product of the reaction below. Include correct stereochemistry. ?  (A) I (B) II (C) III (D) IV (E) V

70. Predict the major product of the following reaction. OH CHO OH acid cat. ? (A)  (B)(C) (D)  (E)

71. Identify the monomer(s) which are used to prepare the following segment of polymer: - CH2CH=CHCH2CH(C6H5)CH2CH2CH=CHCH2CH(C6H5)CH2- (A) CH2=CH2 and CH2=CHC6H5 (B) CH2=CHCH=CH2 and CH2=CHC6H5 (C) CH2=C(C6H5)CH=CH2 (D) C6H5CH=CHCH=CH2 (E) CH2=C=CH2 and CH2=CHC6H5

72. What is the major product for the following reaction (A) (B) (C) (D)  (E)