ATTN: answers to the below questions are due at the start of your second meeting (1/11 or 1/12); these answers should be part of your pre-lab write-up. The first quiz will be in lecture on Tuesday 1/17/2006. 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. Why is sodium hydroxide added in the initial stage of the reaction?

b. How many equivalents of formaldehyde are used in the reaction (using the amounts used in the reader)? Show calculations.

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

d. After removing the solvent, some students will observe a viscous liquid for their crude products, while others will have a solid crude product. Explain why and how each of them will have to proceed.

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

f. Sketch the plate using SiO₂ as stationary phase and a CH₂Cl₂/hexane (1:1) using the same definitions as in e.

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

2. Why does asymmetric synthesis play a very important role in the production of many pharmaceuticals?

3. What is the difference of the "Cram chelate model" and the "Cram Rule"?