ATTN: answers to the below questions are due at the start of your second lab period; these answers should be part of your pre-lab write-up.

Announcements (make sure to read them since you will held responsible to it)

1. The first quiz will be administered in lecture on Monday, January 11, 2010 at 11 am (covering the introduction to asymmetric synthesis and the resolution step). It is the student's responsibility to arrive on time which means that you have to be there at 10:55 am!!!! Late arrivals (even if it is only one minute) will not be allowed to take the quiz, 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! You cannot add the name after time was called because this is considered cheating.

2. The draft version of the paper will be due on Friday, January 29, 2010 at 4:30 pm.

3. The instructor will not respond to anonymous emails. In other words, if you are not providing your name (not just some alias!) with the email, you will not get a response. Make sure that you have a working email registered with URSA to receive class announcements.

4. The questions below are due on January 7, 2010 or January 8, 2010 depending on when your lab section meets.

Questions

1. Referring to the resolution of 1,2-diaminocyclohexane (step 1), answer the following questions.

a. Provide a balanced equation for this reaction including the proper stereochemistry of the reactants and products.

b. When the diamine is added to the acidic solution, a small amount of precipitate is initially observed that dissolves upon further addition of diamine. Explain briefly and show appropriate chemical equations.

c. After the addition of acetic acid, a student only observes the formation of a minute amount of precipitate. What can he do at this point?

d. A different student isolates 4.20 g of the crude tartrate salt. How much solvent should he use to recrystallize the crude? Which solvent is used here?

d. After recrystallization, he obtains 2.10 g of the tartrate salt. Determine the percentage yield for this reaction (assume that he used the quantities given in the reader) and comment on it. Show all calculations.

e. Assuming the specific optical rotation for the pure product is [a]= +12.5^o, determine the optical purity of a sample that exhibits a specific optical rotation of [a]= +8.0^o. Comment on the observed optical purity.

2. Referring to asymmetric synthesis, answer the following questions.

a. Who was the first one to discover that molecules are chiral? Based on which observation? When did this happen?

b. Why is it fairly difficult to separate enantiomers from each other?

c. What is the ultimate goal of asymmetric synthesis? How is this accomplished?

d. Why is it important that single enantiomer drugs are used in many cases?