ATTN: answers to the below questions are due at the start of your second meeting (4/5 or 4/6); these answers should be part of your pre-lab write-up. The first quiz will be administered in lecture on Monday 4/9/2007 at 12 pm. Please make sure that you arrive on time.

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

a. Why it is important to dissolve the sodium hydroxide completely before proceeding? How can this process be sped up?

b.What is the electrophile and what is the nucleophile in this reaction? How are they introduced into the reaction?

c.Why is the mixture cooled down prior to adding the 36% formaldehyde solution?

d. After the reaction is completed, the reaction mixture (usually a brownish oil) is poured into water and the mixture then acidified using 36% hydrochloric acid. Rationalize this step and provide pertinent chemical equations.

e. Dichloromethane is used as solvent for extraction here. How much is appropriate?

f. After removing the solvent, student A observes a viscous liquid as their crude product, while student B obtains a pale yellow solid. Explain briefly. How should each of these students proceed?

f. Sketch the TLC plate (SiO₂, CH₂Cl₂/hexane (1:3)) with the desired product in lane 1, the starting phenol in lane 2 and the salicylaldehyde (product from step 3) in lane 3. What would change if the solvent mixture used would be CH₂Cl₂/hexane (1:1)? What is the purpose of this step when performed on the crude product?