精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰有機化學一 課程性質︰系上必帶 課程教師︰汪根叢 開課系所︰化學系 考試時間︰2006/10/17 是否需發放獎勵金:是 (如未明確表示,則不予發放) 試題 : 1.Please compare the relative proton acidity(pKa) of the following compounds and give your reasons.(10%) H H H O H O | ┌─┐ | ┌─┐ | ∥ ┌─┐ | ∥ ┌─┐ (a) H-C-│H │ H-C-O-│H │ H-C-C-O-│H │ H-C-C-O-│H │ | └─┘ | └─┘ | └─┘ | └─┘ H H H Cl (b) 3HC-CH3 2HC=CH2 HC≡CH 2.(1)Give the IUPAC systematic names of the following compounds.(10%) ∣ ╲╱ Cl ∣ ∣ ∣ ∣ ∣ ∣ ∣ (a) ╱∣╲╱∣╲ (b) ╲╱╲╱╲╱╲╱╲ (c) ╱╲╱╲╱╲╱ ∣ ∣ ∣ ∣ Cl ╱╲ ╱ Br ∣ ╱ ∣ ▕(指向外的粗線) (d) ╱╲ (e) ╱╲ ∣ ∣ ∣ ∣ ╲╱╲ ╲╱╲(這裡是向內的虛線) ∣ Cl ▽ ╱∣╲ (2)Accirding to the following IUPAC names, draw the corresponding structures. (10%) (a)2,3-dimetheyl-5-(2-methylbutyl)decane (b)6-(1,2-dimethylpropyl)-4-propyldecane (c)4-bromo-2chloro-1-methylcyclohexane (d)cis-1-ethyl-3-isopropylcyclopentane (e)cyclopentylcyclohexane 3.(1)Give you reason for which of the following diaxial-substituted cyclohexane has the highest energy.(4%) CH3 CH3 ∣ ∣ ∕╲╱ ∕╲╱ ∕╲╱ ╱╲∕ ╱╲∕ ╱╲∕ ∣ ∣ ∣ ∣ Cl Cl CH3 Cl (2)Draw the most stable conformation of the following molecules.(6%) CH3 CH3 ▕ Cl ▕ ╱╲╱(虛線) ╱╲ (a) ∣ ∣ ﴠ (b) ∣ ∣ ╲╱ (虛線)╱╲╱╲(虛線) ╱∣╲ CH3 CH3 4.(1)Which of the following conformers of isobutyl chloride is the most stable, why?(4%) H CH3 H H CH3 Cl ╲︵︵︵╱ ╲︵︵︵╱ (a) ( ∣ ) (b) ( ∣ ) ( ╱╲ ) ( ╱╲ ) H︶︶︶CH3 H︶︶︶CH3 ∣ ∣ Cl H (2)Draw the most stable and unstable eclipsed conformers of isobutyl chloride.(6%) 5.For chemical reactions shown below, the starting W firstly transforms to intermediates A and B, then subsquently from products C and D. Based on Curtin-Hammett principle explain how you can control the product formation ratio of C to D.(15%) W Ea2 ∣ Ea1 <---- ↓ → Ea3 C → 〔 A ← B 〕→ D given: Ea3 > Ea2 > Ea1 6.Given your reasons for the following observations of bond dissociation energy.(15%) (a) 3HC-X X = F Cl Br I (3%) 138 103 87 71 (b) 3HC-X X = F OH NH2 (3%) 136 119 108 R = CH3CH3 (CH3)2CH (CH3)3C (c) R-H 101 98.5 96.5 (6%) (d) R-Cl 84 84 85 (3%) 7.Based on Hammond postulate, give your reason for the selectivity of the following halogenations.(20%) F ∣ CH3 CH2 CH3 ∣ F2 ∣ ∣ 3HC——H ——→ 3HC——H + 3HC——F ∣ hνor △ ∣ ∣ CH3 CH3 CH3 9 : 1 CH3 CH3 ∣ Br2 ∣ 3HC——H ——→ 3HC——Br only product ∣ hνor △ ∣ CH3 CH3 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 203.69.188.53 srwff:轉錄至看板 NTU-CHSA 10/21 23:14