ATTN: answers to the below questions are due at the start of your second meeting (4/6 or 4/7); these answers should be part of your pre-lab write-up. The first quiz will be in lecture on Tuesday 4/11/2006. Please make sure that you arrive on time since the quiz will be administered in the beginning of the lecture.

1. Referring to step 2, answer the following questions:

a. In the initial phase, the phenol is dissolved in methanol and sodium hydroxide is added. Provide a balanced equation and explain why it is important to dissolve the sodium hydroxide completely before proceeding. Could sodium hydroxide be replaced by sodium carbonate?

b. Which compound is used as the electrophile in this reaction? Why is it used in excess here?

c. After the reaction is terminated, the reaction mixture (usually a brownish oil) is poured in water and the mixture then acidified. Which purpose does this step serve?

d. How much and which solvent is used for the extraction of the product during the work-up procedure? Rationalize your choice.

e. After removing the solvent, some students will observe a viscous liquid for their crude products. Explain why and how they will have to proceed.

f. Sketch the TLC plate (SiO₂, CH₂Cl₂/hexane (1:2)) with your product in lane 1, the starting phenol in lane 2 and the salicylaldehyde (product from step 3) in lane 3.

g. What is used to spot the sample on the TLC plate? What is used to visualize the spots?

2. Why does one enantiomer have a different effect in the human than the other one? Where does this difference play an important role?

3. Sketch a ¹H-NMR spectrum for L-dopa. What type of multiplets do you expect to observe and why?