The Chemical EducatorISSN: 1430-4171 (electronic version) Abstract Volume 19
(2014) pp 278-282 A Multivariable Enzymatic Resolution Laboratory ExperimentEdward J. McIntee*, Betsy J. Hutchinson and Kate J. Graham Chemistry Department, College of Saint Benedict/Saint John’s University, 37 South College Avenue, St. Joseph, MN 56374, kgraham@csbsju.edu Published: 10 September 2014 Abstract. This laboratory experiment involves an enzymatic chiral resolution process using lipase. While other enzymatic resolutions have been previously reported, our experiment uses a variety of acyl donors and substrates resulting in a wide range of possible products. The use of unknowns increases students’ individual responsibility and prevents using a partner’s data analysis. Students purify the unreacted alcohol from the newly formed ester using column chromatography. Students determine the identity of their alcohol and the resulting ester with IR, 1H and 13C NMR spectroscopy and they use optical rotation to determine the extent of resolution. In the student lab report, students comment on the purity of the final sample. This experiment was developed for use in a first year foundation laboratory but it would also be suitable for implementation in a sophomore organic chemistry laboratory.
Key Words: Laboratories and Demonstrations; organic chemistry; inquiry-based/discovery learning; bioorganic chemistry; enzymes; chirality/optical activity; stereochemistry (*) Corresponding author. (E-mail: kgraham@csbsju.edu) Article in PDF format (384 KB) HTML format Supporting Materials: Instructor preparation notes with CAS numbers for chemicals, experimental procedures for students, student procedure for determining optical purity, a table of acyl donors and substrate alcohols, student handouts, prelab quiz and a grading rubric(174 KB).
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