ATTN: answers to the below questions are due at the start of your second meeting (30/9 or 10/1); these answers should be part of your pre-lab write-up. The first quiz will be administered in lecture on Thursday 10/2/2008 at 11 am (covering step 2, step 3 and the introduction to asymmetric synthesis). Please make sure that you arrive on time. Late arrivals will not be allowed into the class room until the quiz is finished, which means that you will receive an automatic zero score for the quiz. If you do not place your name on the quiz to assume authorship, you will receive a zero score as well!

1. Referring to step 2 (Synthesis of 2,4-Di-tert.-butyl-6-hydroxymethylphenol), answer the following questions.

a. In the initial stage of the reaction, the procedure asks to dissolve sodium hydroxide in the methanolic phenol solution. How is this task most efficiently accomplished? Provide pertinent chemical equations. (Hint: Which problem does the student face here?)

b. After the formaldehyde solution is added, the Erlenmeyer flask has to be sealed off during the reaction. Explain briefly. (Hint: What would the student observe if he does not do this carefully enough?).

c. After the reaction is deemed to be complete ( after about 24 hours of stirring), the reaction mixture is poured into water and the mixture then acidified using 36% hydrochloric acid. Rationalize this step and provide pertinent chemical equations.

d. The mixture is then extracted using dichloromethane. Rationalize this choice. How much is used for every extraction and how many extractions are performed?

e. Why is it important to minimize the amount of anhydrous sodium sulfate during the workup?

f. The solvent is removed using low heat and an air stream. How does this method work and which advantages does it have?

g. A TLC is acquired for the crude and for the final product. Which information can the student gather from these TLCs? What is used as mobile phase?

h. The crude product is recrystallized from hexane. Rationalize this choice. How is this step properly carried out?