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

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)

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

73. Which is the best procedure for the preparation of 2,4-dinitrobenzoic acid from benzene? (A) 1. HNO3/H2SO4 2. CH3Br/AlCl3 3. HNO3/H2SO4 4. KMnO4/H+ (B) 1. CH3Br/AlCl3 2. HNO3/H2SO4 3. KMnO4/H+ 4. HNO3/H2SO4 (C) 1. CH3Br/AlCl3 2. KMnO4/H+ 3. HNO3/H2SO4 (excess) (D) 1. HNO3/H2SO4 2. CH3Br/AlCl3 3. KMnO4/H+ 4. HNO3/H2SO4 (E) 1. CH3Br/AlCl3 2. HNO3/H2SO4 (excess) 3. KMnO4/H+

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

75. Which of the following molecules below best fits the fragmentation pattern of the mass spectrum below.  (A) I (B) II (C) III (D) IV (E) V

76. Choose the structure that is NOT an intermediate or product in the Wolff-Kischner reduction of acetophenone. (A)(B)(C)(D)(E)

77. Choose the best alkyne reactant to complete the following reaction sequence. (A)(B)(C)(D)(E)