ATTN: answers to the below questions are due at the start of your second meeting (4/3 or 4/4); these answers should be part of your pre-lab write-up. The first quiz will be administered in lecture on Tuesday 4/8/2008 at 12 pm (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. Even though sodium hydroxide dissolves fairly well in methanol (1 g/4.2 mL MeOH), the dissolution process in this lab is often very slow. Explain briefly why. How it can be accelerated?

b. The solution obtained from the reaction of the phenol with NaOH has to be chilled prior addition of the 36% formaldehyde solution. Explain briefly why.

c. Why is the flask sealed off during the reaction? (Hint: what would the student observe if he does not do this carefully?)

d. After the reaction is deemed to be complete (~20-24 hr 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.

e. How is the solution dried during the workup? Why is it important to use the minimum amount of drying agent here?

f. The instructor recommended in lecture to remove the solvent with the aid of an air stream. How does this method work and which advantages does this have?

g. Prior and after recrystallization, a TLC has to be acquired. What is used as mobile phase? How are the compounds applied to the TLC plate? Which information can the student gather from these two TLCs?

h. The crude product is recrystallized from hot hexane. Rationalize this choice.