课程名称︰有机化学一
课程性质︰化学系大二必修
课程教师︰罗礼强
开课学院：理学院
开课系所︰化学系
考试日期（年月日）︰2021/1/14
考试时限（分钟）：110min
试题 :
1. Explain the relative distribution of products below using energy diagram for
the hydrogen abstraction step that leads to each product. In energy diagrams for
the two pathways, show the relative energies of the transition states and of th
e alkyl radical intermediates that results in each case.
https://i.imgur.com/eadYKyV.jpg
2. Consider the monochlorination of
2-methylbutane.
(a) Assuming that the product mixture was subjected to fractional distillation,
which fractions, if any, would show optical activity?
(b) Could any of these fractions be resolved, theoretically, into enantiomers?
(c) Could the compounds of each fractions from the distillation be identified on
the basis of H-NMR spectroscopy? What specific characteristics in a H-NMR spect
rum of each fraction would indicate the identity of the compound(s) in that frac
tion?
3. How is the endo-/exo- position of a bridged bicyclic compound defined? Use th
e two methyl groups of 2,2-dimethylbicyclo[2,2,1]heptane as an example.
4. Briefly describe the following terms:
(a) conjugated system,
and (b) endiyne antibiotics.
5. What integral values would you expect for signals in H-NMR spectrum for each
of the following compounds?
https://i.imgur.com/wnikLMZ.jpg
6. When 1-hexene reacts with NBS, two products with the formula C6H11Br are obta
ined. What are these two products? Provide a mechanism to account for this obser
vation.
7. What is the major product obtained from each of the following reactions?
https://i.imgur.com/oLxBaTA.jpg
8. Write a mechanism that accounts for the following reaction. Note that the hyd
rogen atom bonded to tin in tributyltin hydride is readily transferred in radica
l mechanisms, and AIBN is a radical initiator.
https://i.imgur.com/T5AbQB9.jpg
9. Which of the following compounds would have a larger coupling constant (J_a,b
). Explain your answers.
https://i.imgur.com/G0ITs6x.jpg
10. Which diene and dienoplile would you employ to synthesize the following comp
ounds?
https://i.imgur.com/igQDugh.jpg
11. Explain why polyunsaturated fatty acids are much prone to autoxidation.
12. Briefly exhaling how you might distinguish between the following substances
by comparing their following H-NMR spectra.
https://i.imgur.com/Sa6aFEh.jpg
13. Deduce the structure of the following compounds based on the spectral data p
rovided. Explain your answers.
(a) Compound P, C4H8O. H-NMR δ 9.76(s, 1H), 2.37(q, 2H), 1.64(m, 2H), 0.97(t, 3
H).
(b) Compound Q, C8H16. The broad-band proton decoupled C-13 spectrum of Q shows
six signals at δ 135(CH), 130(C), 33(C), 32(CH3), 27(CH3), 20(CH3).
(c) Compound X, C7H7Br. H-NMR δ 7.39(d, 2H), 7.06(d, 2H), 2.31(S, 3H).
(d) Compound Y C6H10O. The broad-band proton decoupled C-13 spectrum of Y shows
signals at δ 212 (C), 42(CH2), 27(CH2), 25(CH2).
(e) Compound Z, C10H12O. H-NMR δ 9.90(s, 1H), 7.78(d, 2H), 7.34(d, 2H), 3.15(m,
1H), 1.25(d, 6H); C-13 NMR δ 192(CH), 155(C), 134(C), 130(CH), 127(CH), 36(CH)
, 24(CH3).