Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit

CHEM25A Fall 2023 – Practice Exam 2

1. Draw resonance structures for the following compounds. Be sure to include all lone pairs and use arrows to show the transfer of electrons/charge from one structure to another. Maximum of two arrows per structure. (18 points)

2. Amphetamine is a powerful stimulant of the central nervous system.

a) Based on the pKa values, circle the most acidic proton in amphetamine. (2 points)

b) What products are formed when amphetamine is treated with NaH? Show the reaction scheme. (10 points)

c) What products are formed when amphetamine is treated with HCl? Show the reaction scheme. (10 points)

d) Use an arrow pushing mechanism to demonstrate how bonds are made/broken in question 2b. Show all lone pairs and non-zero formal charges. (10 points)

3. Kianic acid is a molecule from a red Japanese seaweed that binds to glutamate receptors in the brain and kills brain cells.

a) Identify the stereocenters in kainic acid and label each stereocenter with the stereochemical configuration (R or S). (9 points)

b) Calculate the degree of unsaturation in kainic acid. (3 points)

DOU = __3________

4. Draw both chair conformers for the following compound and circle the lower energy conformer. (15 points)

5. List the relationship between the following molecules as enantiomers, diastereomers, constitutional isomers, meso, or the same molecule. (18 points)

Relationship between molecule A and B: ___diastereomers_______________

Relationship between molecule A and C: ___ enantiomers________________

Relationship between molecule A and D: ___diastereomers_______________

Relationship between molecule B and C: ___diastereomers_______________

Relationship between molecule B and D: ___ enantiomers________________

Relationship between molecule C and D: ___diastereomers_______________

6. Draw the line structure of 4-ethyl-5-iodo-2,2-dimethyloctane. (5 points)