CHEM 2325 Exam 4-Version A or B Name:
December 11, 2014 UTEP ID:
Questions 1-12 pertain to the following five structures in the Fischer Synthesis of a carbohydrate starting from glyceraldhyde.
a. b. c. d. e.
1. For sure this is a synthesis of which type of carbohydrate?
a. d b. l c. D d. L e. not a.-d.
2. This is the synthesis of a?
a. hexose b. pentose c. tetrose d. triose e. not a.-d.
3. Structures a.-e. are the intermediates and product in the synthesis of?
a. erythrose b. galactose c. ribose d. threose e. not a.-d.
4. Which intermediate is a cyanohydrin?
a. structure a. b. structure b. c. structure c. d. structure d. e. structure e.
5. Which intermediate is an aldonic acid?
a. structure a. b. structure b. c. structure c. d. structure d. e. structure e.
6. Which intermediate is a lactone?
a. structure a. b. structure b. c. structure c. d. structure d. e. structure e.
7. Which structure is a hemiacetal or lactol?
a. structure a. b. structure b. c. structure c. d. structure d. e. structure e.
8. Which structure is easily epimerized at the anomeric carbon?
a. structure a. b. structure b. c. structure c. d. structure d. e. structure e.
9. To which intermediate would be added Na(Hg) to continue the synthesis?
a. structure a. b. structure b. c. structure c. d. structure d. e. structure e.
10. The product of this synthesis cannot form a?
a. furanose b. pyranose c. both a. and b. d. not a. or b.
11. One structure in this synthesis could be classified as?
a. alpha b. beta c. delta d. gamma e. not a.-d.
12. On further reactions, the product of this synthesis could be used to make?
a. erythrose b. galactose c. ribose d. threose e. not a.-d.
13. Which is the third intermediate in the Ruff Degradation of carbohydrate starting with its open form?
a. b. c. d. e.
14. Which a carbohydrate is alpha-cellobiose?
a. b. c. d. e. not a.-d.
15.-17. Match each reaction sequence to a product on the right. Answers may be repeated. Assume any necessary workup.
15. a. b.
16. c. d.
17. e. not a.-d.
18. What is D in the following reaction sequence? Assume any necessary workup.
a. b. c. d. e. not a.-d.
19. The reaction of Val-Leu with N-phenylthioisocynate followed by trifluoroacetic acid would make?
a. b. c. d. e. not a.-d.
The Exam 4 retake homework will be due Friday, December 12 (Tomorrow!), before 5 pm through http://organic.utep.edu/quiz, no exceptions or excuses. An exam file will also be available from http://organic.utep.edu/courses/2325/exams. Expect an email from me this evening.