PHARMACEUTICAL CHEMISTRY EXAM #1 Februrary 21, 2008

Transcription

1 PHARMACEUTICAL CHEMISTRY EXAM #1 Februrary 21, 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 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

3 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

4 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 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 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 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 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 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 = 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

7 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 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 The compound illustrated below: I Has one basic and one acidic nitrogen II Has two acidic nitrogens III Is a cyclic urea

8 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 = 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] = 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 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)