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. In which of the following properties are enantiomers identical?

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

2. Lanthanoid compounds are often used as chiral shift reagents.

a. How would the ¹H-NMR spectrum of n-hexanol differ if a shift reagent is used compared if it is not used?

b. Give two examples for NMR shift reagents other than the ones mentioned in the reader.

3. Suggest a procedure to resolve a racemic mixture of benzoin in macroscale (e.g. 10 g).

4. How could you assess the success of your resolution performed in 3.?

5. A student isolated strychine from a natural source. He observes an oprtical rotation of -13.3^o for a 5% solution in a 20-cm cell. Calculate the optical purity for his sample.