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Current Topics in Biochemistry/Bioorganic Chemistry
Assignment
This assignment is due Monday March 13 2023 by midnight on Blackboard as a
single, legible PDF file.
Your name and student number:
1. Describe a scientific experiment that shows evidence of how amino acids with slight
enantiomeric excess could have eventually led to a amino acids with high
enantioenrichment [3 marks].
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2. Draw the following major product. In addition, draw the formation of three main byproducts that arise due to quenching of the carbocation formed [6 marks].
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3. In lecture you learned that biology uses an activation strategy to attach amino acids to
tRNAs. Draw a plausible mechanism for the following reaction, and be sure to include
the appropriate byproducts in the product mixture [6 marks].
.
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4. A series of dimeric peptides were synthesized to explore a strategy to target tumor cells
(Bioconjugate Chem. 2011, 22, 1270-1278.). Draw the product of the following reaction
sequence below. (Don’t forget stereochemistry.) [10 marks]
5. What conditions would you need to cleave the previous peptide (question 4) from the resin
and remove all protecting groups [3 marks].
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The Fmoc-protected rink amide resin is available commercially, and can be deprotonated in
a 20% piperidine solution (Bioconjugate Chem. 2008, 19, 802-805.) to yield a primary amine.
a. Draw a mechanism for the following transformation [ 5 marks].
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b. From the deprotected rink-amide resin, design a c. Draw the product of the following
a stereoselective synthesis for the peptide A below [13 marks].C-term thioester reaction [4 marks].