Chem 264 A Name

1. 2- Deoxyribose-5-phosphate aldolase (DERA) is an enzyme that catalyzes the condensation of acetaldehyde with glyceraldehyde 3-phosphate (Shown). Show the mechanism. Build a model and describe how the enzyme must be shaped to facilitate the direction of attack from the nucleophile. I

. DER A

2. Rotundone (shown below) is the molecule responsible for the peppery aroma in peppers. What cyclic diketone will give rotundone from an intramolecular aldol condensation. I

3. Predict the product for the following two reactions: Sterochemistry is crucial! l

1. LDA, THF, -78°C 2. warm to RT

3.

4. H+, EtOH

1. LDA, THF -78°C

4. Suggest a synthesis and each mechanistic step for the formation of Tutocaine hycrochloride starting from 2-butanone. (Hint: the first step requires a reaction learnt solely from a previous quiz.)

0 I

I

5. Look Up the Fischer Indole Synthesis and produce the mechanism below that creates the following indole:

6. Finish the synthesis of (-)-Gabonolide B below: (Note: Product B has significant I R stretches around 3400 cm-1 (broad), as well as two strong IR bands a t 1700 and 1690 cm-1.)

1. LiHMDS, THF -78°C -> reflux

2. H+, H20 - - - - - - - - -

1 b A

n

1 7. Show all possible aldol dehydration products if these 3 reagents were mixed together in the presence of Sodium tert-butoxide.

8. Please circle the most acidic hydrogen in each molecule:

9. Please fill in the products of the synthesis below:

1. LDA, THF 2.

Br ~ 2 1 . t ~ ~ ~ .5ti20 *

3. LDA

10. Predict the ~ r o d u c t :

C

1. NaOH

2. heat

1. NaOH 2. TMS-CI /