課程名稱︰有機化學二
課程性質︰化學系系必修
課程教師︰楊吉水
開課學院：理學院
開課系所︰化學系
考試日期（年月日）︰2009.03.28
考試時限（分鐘）：10:10~12:20 (130)
是否需發放獎勵金：是
試題 :
註：試題中有[Fig**][Spec*]者，請自http://0rz.tw/Dj4RZ下載圖片。
A. 單一選擇題（每題三分，選十題作答，共三十分）
1. In the following compounds, how many pairs of the methylene protons (Ha and
Hb) are diastereotopic?
[Fig01][Fig02][Fig03][Fig04][Fig05][Fig06]
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5
2. How many of the following compounds would give five signals in 13C NMR?
[Fig07][Fig08][Fig09][Fig10][Fig11][Fig12][Fig13]
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5
3. Which of the following series are arranged correctly in order of decreasing
chemical shifts of the following structures?
[Fig14][Fig15]
(A) Ha>Hb>Hc; Hd>He (B) Hc>Hb>Ha; He>Hd (C) Hb>Ha>Hc; Hd>He
(D) Ha>Hb>Hc; He>Hd (E) Ha>Hc>Hb; He>Hd
4. Which of the 1H NMR spectrum of the following compounds would consist of
one triplet, one singlet, and one quartet only?
(A) CH3CHClCH2CH(CH3)2 (B) CH3CH2CHClCH(CH3)2
(C) CH3CH2CHClCH2CH3 (D) CH3CH2C(CH3)ClCH2CH3
(E) CH2ClCH2CH2CH(CH3)2
5. The isomeric ketones shown below can be distinguished based on the number
of signals in their 13C NMR spectra. Which of the following number of
signals is expected?
(I) [Fig16] (II) [Fig17]
(A) 3 for I and 5 for II; (B) 3 for I and 7 for II;
(C) 4 for I and 7 for II; (D) 4 for I and 3 for II;
(E) 5 for I and 7 for II
6. How many signals would the product of the following reaction show in 1H and
13C-NMR, respectively?
NaOCH3 1)NaH
[Fig18] ───→ ─────→
CH3OH 2)CH3-OTs
(A) 4; 4 (B) 4; 5 (C) 5; 5 (D) 5; 6 (E) 6; 6
7. Give the number of the expected signals in the 1H NMR spectra of compounds
I, II, and III, respectively:
(I) [Fig19] (II) [Fig20] (III) [Fig21]
(A) 2, 3, 4 (B) 3, 2, 5 (C) 2, 3, 5 (D) 2, 2, 4 (E) 2, 4, 4
8. How many isoprene units are present in the following compound
(β-carotene)?
[Fig22]
(A) 4 (B) 5 (C) 6 (D) 7 (E) 8
9. How many of the following statements is/are CORRECT?
(1) The two major conformation of 1,3-butadiene is s-cis and s-trans, and
the latter is more stable.
(2) [Fig23] is named trans-2-methoxy-3-methyloxirane
(3) The complex between 18-crown-6 and K+ is less stable that between
18-crown-6 and Na+.
(4) Sulfides can be oxidized to form sulfones.
(5) The 3J coupling constant in a vinyl group is trans protons > cis
protons.
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5
10. Which of the following pairs of structures has the largest difference in
energy?
(A) [Fig24] vs [Fig25] (B) [Fig26] vs [Fig27] (C) [Fig28] vs [Fig29]
(D) [Fig30] vs [Fig31] (E) [Fig32] vs [Fig33]
11. The reaction of 1,2-epoxycyclohexane with phenylmagnesium bromide
C6H5MgBr, after aqueous work up, will give:
(A) 1-phenylcyclohexanol (B) trans-2-phenylcyclohexanol
(C) cis-2-phenylcyclohexanol (D) cyclohexyl phenyl ether
(E) 2-phenylcyclohexanol
12. Which is the major product in the following Diels-Alder reaction?
heat
[Fig34] + [Fig35] ──→
(A) [Fig36] (B) [Fig37] (C) [Fig38] (D) [Fig39] (E) [Fig40]
B. 簡答題（每大題十分，選七大題作答，共七十分）
1. (a) predict the products of light-initiated reactions in CCl4 with
N-bromosuccinimide (NBS) and the following starting materials. (4%)
(1) cis-2-pentene (2) [Fig41]
(b) Draw the structure of NBS, and explain how NBS provides a constant and
low concentration of Br2. (6%)
2. The Diels-Alder reaction of cyclopentadiene with furan (dienophile)
produces two isomeric products A and B. At room temperature, the
kinetic-controlled pathway dominated and the less stable endo isomer B is
the major product. At 81℃, the thermodynamically more stable exo isomer A
is formed.
[Fig42] [Fig42]
A ←────→ [Fig43] ←────→ B
81℃ room
temperature
(a) Draw the structures of A and B.
(b) Draw and explain the reaction energy diagram. (6%)
3. Give the structures of compounds A-I in the following scheme. (1% for A-H)
1)Hg(OAc)2
MeOH D conc. HCl
┌→ B (minor) ─────→ C ─→ [Fig45] ─────→ I
NaOH │ 2)NaBH4
[Fig44] ───┤ +
Heat │ MCPBA [Fig46] H3O+ 1)NaH
└→ A (major) ───→ E ────→ ──→ F ────┐
ether 2)CH3I │
│
┌──────────────┘
│
│ excess HBr
└→ [Fig47] ─────→ G + H (gas)
heat
4. The Mass spectrum of a compound (CxHyOz) shows molecular ion peak at m/z =
136. The following show its IR and 1H NMR spectra.
(a) Propose a structure for this compound. (4%)
(b) Assign the peaks of the 1H NMR spectrum. (4%)
(c) Explain the origin of the IR peaks in the regions 3200-3600 and
600-800 cm-1. (2%)
[Spec1][Spec2]
5. (a) A compound with molecular formula C5H12O2 has strong infrared
absorption in the region 3300-3400 cm-1. Its 1H NMR spectrum has three
singlets at δ0.9, δ3.45 and δ3.2 with an area ratio 3:2:1. The 13C
NMR spectrum shows three signals all at higher field than δ100. Give a
structure consistent with all these information. (6%)
(b) Both the compounds A and B are shown below have a methyl group. Which
of the methyl protons possess a larger chemical shift in 1H NMR?
Explain your answer. (4%)
(A) [Fig48] (B) [Fig49]
6. The following 13C-NMR, 1H-NMR, IR and Mass spectra are taken from a
compound (CxHyOz). Determine the structure (4%), assign the 1H-NMR peaks
(4%), and accound for the Mass peaks at m/z = 119 and 149. (2%)
[Spec3][Spec4][Spec5]
7. Define the following fragmentation reactions in Mass Spectroscopy:
(a) α-cleavage of triethylamine (NEt3). (2%)
(b) McLafferty rearrangement of 2-pentanone (CH3COCH2CH2CH3). (3%)
(c) Retro-Diels-Alder of cyclohexane. (2%)
(d) Four-Ring rearrangement of [Fig50] (3%)
8. Provide structures that are consistent with the provided spectra. (5% for
each)
(a) [Spec6] (b) [Spec7]
9. (a) Predict the splitting pattern for compound 3,3-dimethylbut-1-ene
(structure shown below) by drawing tree diagrams for the three protons:
Ha, Hb, Hc. (6%)
(b) How do you use the DEPT technique to assign the peaks of carbins C' and
C". (4%)
[Fig51]
Over, Good Luck!
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 118.166.8.129