Spectroscopy

The Final Exam Spring 2022

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2. You have just been promoted to head of analytics for the Drug Enforcement Agency.

While your officers are usually able to identify drugs by matching their IR signatures, or

barring that electrospray ionization mass spectrometry, a mysterious new compound has

come in that doesn’t match any of the known structural data. The drug seems to behave

like an opioid, but is more potent and longer acting than the closest match. Using the

available characterization, determine the identity of Unknown A. For full credit you

must label all of the relevant peaks in the spectra, denote important crosspeaks, and

write down all of your work that led you to your assignment! (35 pts)

ESI-MS (+)

IR

Other data available: 1H NMR, 13C NMR, COSY, NOESY, HSQC, HMBC

The Final Exam Spring 2022

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Please use this space to write your work for Question 2/Unknown A (attach (an)

additional page(s) if necessary):

The Final Exam Spring 2022

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3. While working in the Li group here at UT trying to develop some bromonium-based

catalytic reactions, you isolate a byproduct (Unknown B). Using all of the

characterization available, discern the identity of Unknown B. For full credit you must

label all of the relevant peaks in the spectra, denote important crosspeaks, and write

down all of your work that led you to your assignment! (25 pts)

EI-MS (+)

Other data available: 1H NMR, 13C NMR, gCOSY, NOESY, HSQC, gHMBC

The Final Exam Spring 2022

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Please use this space to write your work for Question 3/Unknown B (attach (an)

additional page(s) if necessary):

The Final Exam Spring 2022

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4. Label all of the peaks for the drug amoxicillin. For full credit you must label all of the

relevant peaks in the spectra, show crosspeaks, and write down all of your work that

led you to your assignment! (10 pts)

Data available: 1H NMR, 13C NMR, gCOSY, NOESY, HSQC, gHMBC

Please use this space to write your work for Question 4 (attach (an) additional page(s) if

necessary):

Structure of amoxicillin

5. Several protons don’t appear in the NMR spectrum for amoxicillin. Which protons are

these (circle or otherwise denote), and why do they not show up (be as specific as

possible)? (5 pts)

The Final Exam Spring 2022

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6. While screening some plant extracts, your medicinal chemistry colleague has

discovered one fraction that readily inhibits malaria infection in a model organism. After

you get the responsible compound from the separations group, your goal is to determine

the identity of this compound. A preliminary MS suggests that you could have one of the

cinchona alkaloids, but you cannot determine the stereochemistry based solely on MS

data. Using all of the characterization available, match the protons and carbons to their

relevant peaks, and offer a structure with defined stereochemistry. Beware, the use of

DMSO-d6 as a solvent has possibly obscured some of your peaks! For full credit you

must label all of the relevant peaks in the spectra, denote relevant crosspeaks, and write

down all of your work that led you to your assignment! (20 pts)

Other data available: 1H NMR, 13C NMR, gCOSY, NOESY, HSQC, gHMBC

Please use this space to write your work for Question 6 (attach (an) additional page(s) if

necessary):

Structure of cinchonine

The Final Exam Spring 2022

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Please use this space to continue writing your work for Question 6 (attach (an) additional

page(s) if necessary):

The Final Exam Spring 2022

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The Final Exam Spring 2022

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