PHARMACEUTICAL CHEMISTRY EXAM #1 Februrary 21, 2008 1 Name SECTION B. Answer each question in this section by writing the letter corresponding to the best answer on the line provided (2 points each; 60 points total) USE THE REVERSE SIDE OF YOUR SCANTRON SHEET TO ANSWER QUESTIONS IN SECTION B. 1. The compound shown below: I Contains a carbonate functional group II Is acidic with a pk a = 9 III Contains a carbamate functional group 2. The compound illustrated below: I Has an exocyclic double bond with (Z)- stereochemistry II Possesses a primary amine group III Has an exocyclic double bond with (E)- stereochemistry 3. For the structures illustrated below: Cl O H 2 N CH 3 O CH 2 CH 2 N A CH3 H 2 N O CH 3 I Compound B has a higher (more positive) log P than compound A II Compound B has a conjugate acid that has a pk a of 9 III Compound A is more lipophilic than compound B O CH 2 CH 2 N CH3 B
2 4. The compound illustrated below: I Is shown in its least stable conformation II Has two bromines that are in a gauche conformation III Is shown as a partly eclipsed conformation 5. The compound illustrated below: I Contains a sulfide functional group II Has one chiral center with (S)- stereochemistry III Contains a lactam functional group 6. The compound shown below: I Has the lone pair of electrons associated with the nitrogen in the same plane as the ring II Is aromatic III Is a base with pk b = 10 (Hint: A + charge on a carbon atom is represented as a vacant p-orbital) 7. For the structures illustrated below: I Conformation B is lower in energy than conformation A II The methyl group and alcohol group are cis- to one another III Conformation A is lower in energy than conformation B
8. The compound illustrated below: I Is the conjugate base of a sulfonic acid II Has a pk b value = 5 III Has a conjugate acid form that is a sulfonamide 3 9. The compound illustrated below: I Is a meso isomer II Has (R)-stereochemistry at the chiral center closest to the carboxylic acid group III Is the D-enantiomer 10. Consider the two structures shown below: I Compound A has a higher pk b than compound B II Compound B is a stronger base than compound A III Compound A is a stronger base than compound B 11. The compound shown below: I Contains only two aromatic rings II Contains a lactone functional group III Contains three aromatic rings
12. The compound illustrated below: I Has a conjugated acid with a pk a = 11 II Is a cyclic amidine III Contains a tertiary amine functional group 4 13. For the compound illustrated below: I The methyl groups are in a gauche conformation II The methyl groups are anti III The structure shown is the lowest energy conformation for this compound 14. The compound illustrated below: I The hybridization of the nitrogen is sp 2 II The pk b = 12 III The hybridization of the nitrogen is sp 3 15. In the structure illustrated below: I II III There is an imide functional group There is one chiral center There is a urea functional group
5 16. The compound illustrated below: I The lone pairs on the oxygen are in a plane that is perpendicular to the methyl groups II The hybridization of the oxygen is sp III The hybridization of the carbon next to oxygen is sp 2 17. For the structures illustrated below: I Compound B is more reactive (higher in energy) than compound A II Compounds A and B both contain an ether functional group III The phenyl groups of compound B are cis 18. For the two compounds illustrated below: I The specific rotation [α] of compound B is -13 II The boiling point of compound B is 99 C III Compound A is a (S)-stereoisomer 19. The compound illustrated below: I Contains an imine functional group II Contains an amidine functional group III Contains two nitrogens that behave as bases in water
6 20. For the structures shown below: I Compound A has a lower pk a than compound B II Compound A forms a conjugate base that can be stabilized by resonance III Compound B is a weaker acid than compound A 21. In the compound illustrated below: I The three oxygen atoms are in the same plane II There is a carbonate functional group III The ring is aromatic because of the one double bond and the two lone pairs from the ring oxygens a) only 22. The structure shown below: I Contains exactly three chiral centers II Contains an ester functional group III Has a conjugate base form that has a pk b = 5 23. For the structures shown below: I Compound B is a stronger acid than compound A II Compounds A and B both contain an amide functional group III Compound A is a stronger acid than compound B
24. The compound illustrated below: H CH 3 I Undergoes dissociation in water to form a strong base N N II Has a pk a of 13 N III Is a cyclic guanidine 7 25. The compound illustrated below: I Is an aromatic heterocycle II Has a nitrogen that functions as a base in water III Has both lone pairs on the oxygen contained in p-orbitals 26. The compound illustrated below: I Is an acid with a pk a = 9 II Is a cyclic imide III Is a cyclic amide 27. The compound illustrated below: I Is 50% ionized at ph 12 II Contains a thiol functional group III Is 50% ionized at ph 2 28. The compound illustrated below: I Has one basic and one acidic nitrogen II Has two acidic nitrogens III Is a cyclic urea
29. The compound illustrated below: I Has a nitrogen that is in conjugation with the benzene ring II Contains a sulfonamide functional group III Has a pk a = 7 30. The compound illustrated below: N H I Is 50% ionized at ph 9 II Is 100% ionized at ph 9 III Is 50% ionized at ph 5 SECTION C. 9 Points Total. a) The compound in the center below is the sugar galactose. It has an optical rotation [α] = +798. Write the stereochemistry (R or S) at each chiral center of galactose (center structure only). Then answer the questions below. 8 a) What is the relationship (enantiomer, diastereomer, or same compound) of Compound B to the galactose structure shown above? b) Would the optical rotation of Compound B be: +79, -79, 0, or is there not enough information to determine it? c) Explain your answer from question b). d) Is the galactose structure shown above the D- or L-enantiomer? e) Would the melting point of Compound B be: 168 C, -168 C, 0 C, or is there not enough information to determine what the melting point would be?
9 SECTION D. For each of the following pairs of compounds circle the one that has the higher log P. (6 points). a) b) c) d) e) f)