110年 - 110 國立臺灣大學_碩士班招生考試_部分系所:有機化學(A)#102031

選擇題 (25)

1.How many chiral centers can be found in the structure of Taxol drawn below?
(A)10 (B) 11 (C)12 (D) 13

2. How many of the following statements is/are correct?
(I) Gauche form is the most stable conformer of butane.
(II) In cyclopropane, the maximum electron density between two carbon atoms corresponds to the internuclear axis.
(III) According to Bacyer strain theory, cyclopentane has greater angle strain than cyclohexane. (A)0(B)1 (C)2 (D)3

3. How many of the following statements is/are correct?
(I) The cis form of 1,3-dimethyI cyclohexane is more stable than the trans form.
(Il) In cyclohexane, the boat form conformer is more stable than the twist-boat forn.
(III) The 1,3-diaxal interaction in cyclohexane is mainly resulted from the torsional strain. (A)0(B)1 (C)2(D) 3

4.How many of the following statements is/are correct?
(I) Meso-tartaric acid can rotate plane polarized light.
(Il) Nitrogen and sulfur atoms can be chiral centers.
(III) A racemic mixture can't rotate plane polarized light. (A)0 (B)1 (C)2 (D)3

5.How many of the following statements is/are correct?
(I) Normally, aryl and vinyI halides are good substrates for S_N2 reactions.
(II) S_N2 and S_N1 reactions prefer protic and aprotic solvents, respectively.
(III) Both E1 and S_N1 reactions produce carbocations in their reaction pathways. (A)0 (B)1 (C)2 (D)3

6.How many of the following statements about 1-bromo-2-methyI cyclohexane is/are correct?
(I) The cis form is more stable than the trans form.
(II) Using base to eliminate the trans form should afford lots of Hoffinan product.
(II) Using base to eliminate the cis form should majorly afiord Zaitsev (or Sayizeff) product. (A)0 (B)1 (C)2 (D)3

7. How many of the following assignments is/are correct?(A)0(B)1(C)2(D)3

8.Which of the listed molecules has the highest frequency of the HOMO→ LUMO transition? (A)(B) (C)(D)

9. About the following transformation, how many of the statements is/are correct?

(I) Step (I) is a homogeneous catalytic reaction.
(Ⅱ) The major product in step (2) has a boron atom attached to the benzylic position.
(Ⅲ) Product P is a primary alcohol. (A)0 (B)1 (C)2 (D)3

10. How many of the following compounds is/are aromatic?
(A)1 (B)2 (C)3 (D)4

11. How many of the following compounds is/are more basic than triethylamine?(Ⅰ ) pyridine (II) pyrole (IIl) sodium methoxide (IV) lithium diisopropylamide (A)1 (B)2 (C)3 (D)4

12. How many of the following reagents should transform cyclohexene to alcohol after normal workup? (I) BH₃then H₂O₂/OH^-(II) OsO₄then NaHSO₃ (III)Hg(OAc) ₂then NaBH₄ (IV) MCPBA then H₂O/H⁺(A)1 (B)2 (C)3 (D)4

13. How many of the following statements about radicals is/are correct? (I) Radicals can be generated efficiently in the presence of BHT. (I) ABIN is a common radical initiator. (III) In the step of radical propagation, both heat and the number of free radicals increase. (A)0 (B)1 (C)2 (D)3

14. Which of the following compounds would not undergo racemization in base? (A) (S)-3-methy1-4-heptanone (B) (S)-3-ethy1-2-heptanone (C) (R)-4-cthyl-2-heptanone(D) (R)-2,4-dimethy1-3-heptanone

15. Which is the major product of the following reaction?
(A)(B)(C)(D)

16. Among the following solvents, which is the best for the reaction of I-bromohexane with sodium azide?(A)dimethyIsulfoxide (B) methanol (C) hexane(D)toluene

17. Which of the following transformations might be used to synthesize the following substance?(A)(B)(C)(D)None of abover answers

18. What is most likely to be the final product when cyclopentene is subjected to the following reaction scquence: (I) H⁺/H₂O；(II) PCC；(IIl) piperidine； (IV) NaBH₃CN?(A)(B)(C)(D)

19. How many of the following transformations is/are likely to be practical?
(A)0 (B)1 (C)2 (D)3

複選題
20. How many of the following statements regarding bromination (Br₂/FeBt₃) of toluene is/are correct? ( A ) Reaction begins with the complexation of bromine with the FeBr₃ ( B ) Formation of Br⁺ ion is not the rate determining step ( C ) Addition of Br⁺ to toluene to form the arenium ion is the rate determining step ( D ) 4-Bromotoluene is formed by losing a hydride from the arenium ion (A)1 (B)2 (C)3 (D)4

21. How many of the following reaction sequences can properly achieve the transformation below?

(I) (i) CH₃COCI/AICI₃； (ii) HNO₂/H₂SO₄；(iii) CH₃MgBr； (iv) H₃O⁺/heat
(Ⅱ) (i) CH₃COC/AICl₃； (ii) CH₃MgBr, Et₂O； (ii) H₃O⁺/heat, (iv) HNO₃/H₂ SO₄
(Ⅲ) (i) CH₃COCV/AICI₃； (ii) HNO₃/H₂SO₄； (ili) CH₂-PPh₃ (A)0(B)1 (C)2 (D)3

22. Which of the following is not prominent in the mass spectum of 2-methy1-2-butanol? (A)M-12 (B) M-15 (C)M-I8 (D) M-29

23. Which of the following compound is the most reactive toward nucleophilic ar sromatic substitution? (A) 4-fluoro-1,2-dinitrobenzene (B)1-luoro-2,4-dinitrobenzene (C) 2-luoronitrobenzne (D) no reaction for all above answers

24. Which of the follwoing molecules would not be considered a bicyclic molecule?(A)(B)(C)(D)

25. Calculate the degrees of unsaturation for a molecule with the molecular formula. (A)4 (B)5 (C)6 (D)7

申論題 (8)

1. Assign the C-Hi bond dissociation energy (kcal/mole) listed below to the three differnet radicals. Explain the size of the other two values relative to that for the H-CHs bond. (5 分)

2. Determine the structure compound CioH 1202 based on the following spectroscopic data.(5分)
NMR (δ, ppm): 11, 22, 67, 128, 130, 131, 133, 167;
¹H NMR (δ, ppm): 1.02 (triplet, 3H), 1.80 (sextet, 2H), 4.17 (triplet, 2H), 7.12-7.27 (multiplet, 3H), 7.96-8.08 (multiplet, 2H);
IR (selected peaks; cm"): 3040, 2950, 1730, 1550, 1450, 1280, 1100, 700.

3. The following compound release CO₂ and H₂O after being heated at 230℃. Draw the structure of the most possible reaction product.(5分)

(a)

(b)

(c)

(d)

(e)

110年 - 110 國立臺灣大學_碩士班招生考試_部分系所:有機化學(A)#102031

試卷資訊

選擇題 (25)

申論題 (8)