1. a. Since both compounds travel further, the more polar solvent mixture was used in the development for plate 1 which is in this case, the 3:1 mixture.

b. A separation is very difficult to accomplish if the spots are too close together like on plate 1. Hence the solvent mixture is not suitable to separate teh alkene and teh epoxide, especially on a short column.

c. The student needs to mix 150 mL of dichloromethane and 90 mL of pentane to get 240 mL of a solvent mixture (5:3).

2. a. An appropriate range for absorption reading would be 0.1 < A < 1.0 (one magnitude), since Beer's Law only is valid for dilute solutions and the detector of the UV instrument only response linear in a certain range. The peak at l=340 nm is the most intense one. Assuming the use of a 1 cm cuvette, the concentrations are given

c=A/(e*l)=8.3 *10^-5 mol/L (max, A=1) and 8.3*10^-6 mol/L (min, A=0.1) for e=12000.

b. The same argument as above applies here as well, but with e=1500 leading to c=6.67*10^-4 mol/L (A=1).

c. The best technique would be to use mixed melting points. Alternatively, TLC could be used, but the proper solvent system has to be determine first.

3. a. In order to separate racemic malic acid, it has to be converted into diastereomers. The easiest would be to readt it with a chiral base e.g. brucine to form diatereomeric ammonium salts. Alternatively, the eantiomers could be converted into diastereomeric esters. The separation is then based on different physical properties of the diastereomers e.g. solubility or boiling points.

b. c=0.3 g/10 mL=0.03 g/mL

a=+0.35^o/(0.03 g/mL*0.5 dm)=+23.3^o

optical purity=+23.3/27=86%

c. Half of the total amount started with =5 g of the R-isomer

d. This question can not be answered since there is no information given about the direction of the rotation of either enantiomer. There is no correlation between the stereochemistry and the direction of the rotation.

4.a. The nitration reaction is highly exothermic. The nitronium ion itself is a very strong electrophile, which easily can lead to polynitration. The activation energy for the dinitration is only slightly higher than the one for the mono-nitration.

b. N₂O₅, mixture of sulfuric acid and nitric acid, NO₂⁺BF₄ or NO₂⁺PF₆^-, nitric acid alone

c. The best tool is teh IR spectrum, which should show two additional strong peaks in the range from 1300-1400 and 1500-1600 cm^-1.

d. Yes. It interferes with the formation of the nitronium ion since it is one of the products.

5.a.

b. The carbonyl group is a much stronger electrophile than the the -CH₂Cl function.Hence, the carbonyl group reacts much faster than the other group leading to an amide and not to an amine.

c. To deprotonate the protonated form of the amide.

d. The most important change occurs for the acid chloride since it is very sensitive to moisture. It easily converts into the acid, which in turn forms a an ammonium salt with the 2,6-Dimethylaniline, instead of an amide.

6.

7. a. Below a pH~9.5, the chlorination is a major side reaction. Hence, the reaction mixture has to be buffered with a phosphate buffer to avoid this to happen. Another side reaction, but occuring at much lower pH-values is a rearrangement reaction as well as the hydrolysis of the epoxide to form diols.

b. Most of the used alkenes possess conjugated double bonds that have transitions in the range above 254 nm. The epoxides usually only have a benzene ring that does not absorb light in the range above 254 nm. As a result, they can not be detected in the UV light. You used the ceric staining method to visualize them, which resulted in blue spots.

c. 1 g styrene = 9.6*10^-3 mol (C₈H₈= mw=104 g/mol)

catalyst=10% mol of 9.6*10^-3 mol=9.6*10^-4 mol=0.61 g

N-pyridine oxide=20% mol of 9.6*10^-3 mol=1.92*10^-4 mol=0.182 g (mw=95g/mol)

8. a. Degree of unsaturation = 2

b.

c.

d.

e. 3,4-Dihydropyran

9. The lower wavelength of the C=O stretching frequency in the ortho and para substituted compound originates from the resonance with the OH group. The C=O bond character decreases and as a result, the C=O frequency decreases. The meta isomer does not show this resonance. The ortho isomer also shows weaw hydrogen bonding in addition which lowers it even more.