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

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

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

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) 

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)