last updated Friday, October 14, 2005

Problems Set #6

ATTN: answers to the below questions are due at the start of your lab period of Meeting 6; these answers should be part of your pre-lab write-up.

Announcements:

1. The next quiz will be on October 17, 2005 at 12 pm. The material covered will mainly include the ligand and catalyst synthesis, characterization and the theoretical aspects.

2. The draft version of paper is due on 10-28-2005 at 5 pm. The draft version is worth 15 points, the final paper 45 points. For more information what the draft is supposed to contain see here. Late submission will receive less credit. The more of your work you submit here, the more feedback you will get, which will beneficial for the final version. We will try to return the reports by Monday.

1. Referring to the epoxidation reaction carried out in the lab,

a. why is bleach used in the reaction? Which advantages/disadvantages does this approach have?

b. why is a two-phase system used in this reaction?

c. why is hexane added during the work-up?

d. why is TLC used in this reaction?

e. How is the epoxide visualized in the TLC experiment?

2. A student plans to use 1.2 g of 4-chloro-a-methylstyrene for his epoxidation. His procedure requires the use of 8 mole% of the Jacobsen catalyst and 1.25 equivalents of bleach.

a. How many grams of the catalyst are needed in this reaction?

b. What is the volume of bleach required in this experiment?

c. Your fellow student decides to use hexane as a solvent here. What would you tell him/her?