課程名稱︰有機化學一
課程性質︰化學系必修
課程教師︰羅禮強
開課學院：理學院
開課系所︰化學系
考試日期（年月日）︰2020/10/29
考試時限（分鐘）：120min
試題 :
1. Describe the following terms:
(a) Optical activity
(b) Terminal alkynes
(c) Meso compounds
2. Write an equation for the reaction between each Lewis acid-base pairs and sho
w the electron flow with curved arrows:
(a) HCHO+HCl
(b) BF3+CH3OH
3. Name the following compunds (including stereochemistry).
https://i.imgur.com/FCdm4Or.jpg
4. Draw a dash-wedge structure for the following compounds.
(a) (3S,5R)-5-fluro-3-isopropylcyclohex-1-ene
(b) (2S,3S,4R)-2,4-dibromo-3-methylhexane
(c) tert-butyl iodide
5. Draw Fischer projection for the following compound. Designate the R/S configu
ration at each stereocenter in the structure, and show how they are determined.
https://i.imgur.com/QQmYPOj.jpg
(最右邊的取代基是-CHO)
6. Draw a free-energy diagram for a hypothetical Sn2 reaction. Assume it is high
ly exergonic, and you don't need to provide specific values. Please label the fo
llowing on the diagram:
(a) ΔG nod
(b) ΔG double dagger
(c) transition state
7. The structure of L-fucose, which is a sugar component of the determinants of
the A,B,O blood group typing, is shown below.
(a) Draw the alternative chair conformations of L-fucose.
(b) Which of them is more stable? Explain.
https://i.imgur.com/90FVZtt.jpg
8. If the optical rotation of a new compound is measured and found to have a spe
cific rotation of +40 degrees, how can you tell if the actual rotation is not re
ally +40 degrees plus some multiple of 360 degrees? In other words, how can you
tell if the rotation is not actually a value such as +400 or +760 degrees?
9. Draw the possible chair conformers for the following cyclohexane derivatives.
Indicate which conformer is most stable.
https://i.imgur.com/NgkyA9O.jpg
10. For a a nucleophilic substitution reaction, we have introduced two different
mechanisms, namely, Sn1 and Sn2. Please compare these two mechanisms of the fol
lowing aspects:
(a) rate determining step
(b) outcome of the stereochemistry
(c) timing of bond formation and breakage.
11. Identify the relationship between the following pairs of structures.
https://i.imgur.com/W0i633z.jpg
12. A compound X with the molecular formula C8H16 is optically inactive but can
be resolved into enantiomers. On catalytic hydrogenation, X is converted to K(C8
H18) and K is optically inactive. Propose structures of X and K. Show how you de
duce your answers.
13. Draw the two chair conformers (including all hydrogens of the ring) for the
compound shown below. Provide explanations, based on their conformational analys
is, showing one conformer is more stable than the other.
https://i.imgur.com/xHKTRvi.jpg
14. Assign priorities to the groups in each set:
(a) -CH2CH=CH2, -CH2CH3, -CH=CH2-, -CH2COOH
(b) -NH2, -SH, -OH, -Cl
(c) -OPO3H2, -CHO, -OH, -N(CH3)2
15. A compound Y with the molecular formula C15H14, is known not to contain any
triple bond.
(a) What is the index of hydrogen deficiency of Y?
(b) When Y is subjected to catalytic hydrogenation using an excess of hydrogen,
1 mol of Y absorbs 3 mol of hydrogen and produces a compound with the formula C1
5H30. How many double bonds and rings does a molecule of Y have? Show how you de
duce your answers.
16. Arrange the following in order of increasing basicity:
(a) CH3-, CH3CH2O-, CH3CO2-
(b) (CH3)3N, CH3CH2NH-, CH3CH2NH3+
The pKa value of some organic compounds and structures of the corresponding conj
ugate bases are given below for your reference.
https://i.imgur.com/4Dp7Jq5.jpg