EXAM 1

Question 1

From the following condensed structures, draw the compounds using appropriate skeletal (line-angle) structure representation:

Answer 1

Question 2

From the following condensed structures, draw the compounds using appropriate skeletal (line-angle) structure representation:

Answer 2

Question 3

Provide the molecular formulas for the following molecules:

Answer 3

Question 4

Provide the molecular formulas for the following molecules:

Answer 4

Question 5

For Xarelto, please clearly draw in ALL of the implied lone-pair electrons on the structure.

Answer 5

Question 6

For each pair, circle the molecule with the lower pKa and provide a brief explanation for your choice. The hydrogen in question is in bold.

Answer 6

Question 7

For each pair, circle the molecule with the lower pKa and provide a brief explanation for your choice. The hydrogen in question is in bold.

Answer 7

Question 8

For each pair, circle the molecule with the lower pKa and provide a brief explanation for your choice. The hydrogen in question is in bold.

Answer 8

Question 9

For each pair of resonance structures, (i) use the curved-arrow formalism to show electron-pushing to convert the structure on the left to the one on the right. (ii) Circle the major resonance structure contributor and (iii) provide a brief rationale for your answer (1 sentence or less).

Answer 9

Question 10

For each pair of resonance structures, (i) use the curved-arrow formalism to show electron-pushing to convert the structure on the left to the one on the right. (ii) Circle the major resonance structure contributor and (iii) provide a brief rationale for your answer (1 sentence or less).

Answer 10

Question 11

The following reactive intermediate molecule has three additional resonance structures. Depict these resonance structures using the curved-arrow formalism to push electrons. Circle the major structure.

Answer 11

Question 12

For the following acid/base reaction, please identify the acid (A), base (B), conjugate acid (CA), and conjugate base (CB) in the provided boxes.

Answer 12

Question 13

In the reaction below:
(a) Draw the structures corresponding to the appropriate conjugate acid and conjugate base. Please place your answers in the boxes provided below.

(b) Use the curved-arrow formalism to provide an arrow-pushing mechanism to depict the movement of electrons.
(c) Draw the equilibrium arrows for this reaction in the dotted box below to show which side the equilibrium will lie.
(d) Using 1-2 sentences, briefly rationalize why the equilibrium in the above reaction favors the direction you drew. Pictures/structures may be used to help support your answer.

Answer 13

Question 14

Name this functional group

Answer 14

amide

Question 15

Name this functional group

Answer 15

amine

Question 16

Name this functional group

Answer 16

ether

Question 17

Name this functional group

Answer 17

alkene

Question 18

Name this functional group

Answer 18

alcohol

Question 19

Name this functional group

Answer 19

ester

Question 20

Name this functional group

Answer 20

alkyne

Question 21

Name this functional group

Answer 21

carboxylic acid

Question 22

Name this functional group

Answer 22

ketone

Question 23

Choose the correct IUPAC name for the following molecules:

Answer 23

Question 24

Choose the correct IUPAC name for the following molecules:

Answer 24

Question 25

Choose the correct IUPAC name for the following molecules:

Answer 25

Question 26

Assign the chiral carbons in the following drug molecules as either R or S. Please write your answers in the boxes provided.

Answer 26

Question 27

Assign the chiral carbons in the following drug molecules as either R or S. Please write your answers in the boxes provided.

Answer 27

Question 28

Identify the stereochemical relationship between the following pairs of isomers. State whether the molecules are: identical, constitutional isomers, enantiomers, or diastereomers. Please write your answer on the blank provided.

Answer 28

Question 29

Identify the stereochemical relationship between the following pairs of isomers. State whether the molecules are: identical, constitutional isomers, enantiomers, or diastereomers. Please write your answer on the blank provided.

Answer 29

Question 30

Identify the stereochemical relationship between the following pairs of isomers. State whether the molecules are: identical, constitutional isomers, enantiomers, or diastereomers. Please write your answer on the blank provided.

Answer 30

Question 31

Identify the stereochemical relationship between the following pairs of isomers. State whether the molecules are: identical, constitutional isomers, enantiomers, or diastereomers. Please write your answer on the blank provided.

Answer 31

Question 32

The structure of (S)-1-chloro-2,3,3-trimethylbutane is provided below. Use the circles provided to draw the Newman projection for each staggered conformation, sighting along the C1-C2 bond. Clearly label both the most stable and least stable staggered conformer. Briefly explain your reasoning.

Answer 32

Question 33

a) Draw the equilibrium reaction between both chair conformers of cis-1-ethyl-4- isopropylcyclohexane (shown below). Make sure to clearly draw in axial and equatorial substituents when necessary.

b) deltaG values, are known to be additive. This allows you to calculate the population difference of a cyclohexane system bearing multiple substituents. For the molecule above, (i) calculate the Gibbs free energy (DGrxn) for the equilibrium reaction above. Please show all your work, including all units, for full credit. (ii) Circle the most stable conformer in the above reaction.
A Values (kcal/mol): ethyl (1.75), isopropyl (2.15) 
DGrxn = -RT ln Keq
R = 0.001987 kcal mol-1 K-1

Answer 33