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.

1. Why are molecules with a specific stereochemistry important to us? Explain briefly.

2. In which of the following properties are enantiomers identical?

a. Melting point
b. Retention time on chiral column
c. NMR spectrum in CD₂Cl₂
d. optical rotation

3. Most of you have performed the reduction of camphor in Chem 30BL/130 AL. This reaction lead to a mixture of isoborneol and borneol. Rationalize this observation by showing appropriate diagrams.

4. Suggest a procedure to resolve a racemic mixture of 2-amino-1-butanol. What is the specfic optical rotation [a]_D²⁰ for the (S)-form?

5. Which criteria are important when designing an asymmetric synthesis?

6. Why is it important that you add the 30% hydrogen peroxide solution slowly to the cerium hydroxide suspension?

7. A student isolated a compound from a natural source. The observed rotation a of a 0.6 g sample of cholesterol in 25 mL of methanol solution contained in a 10 cm polarimeter tube is -3.2^o. Calculate the specific rotation [a]_D²⁰.

8. A student isolated the Jacobsen ligand from his reaction. He dissolves 0.6 g in 10 mL of dichloromethane and places the solution in a 1 dm-cell. The observed value is 16.9^o.
a. Calculcate the optical purity for his sample assuming that the specific rotation for the pure ligand is [a]_D²⁰= -315^o.
b. How much (in %) of the (R,R) and the (S,S)-form are present in the product?