5.32 is a 15 unit class. Experimental work more advanced than in 5.310 or 5.311, emphasizing organic synthesis assisted by chiral catalysis, purification, and analysis of organic compounds employing such methods as IR, 1D and 2D NMR, UV spectroscopies and mass spectrometry, and thin layer and non-chiral and chiral gas chromatography. Also experiments involving enzyme purification, characterization and assays, as well as molecular modeling in organic synthesis and in biochemical systems.
Prof. Alexander M. Klibanov
Laboratory Director
Dr. Mircea D. Gheorghiu
1. Asymmetric Catalysis of Diels-Alder Reactions (
PDF). Diels Alder Appendix (
PDF)
This experiment involves the asymmetric Lewis acid catalyzed Diels-Alder cycloaddition of an α,β-unsaturated carbonyl compounds to a cyclic or acyclic diene. A chiral boron catalyst is synthesized starting from L- or D-tartaric acid. The ee is assessed by chiral GC and/or polarimetry. The relative thermodynamic stabilities of the exo- and endo-diastereomers, and the structure of the complexes of the boron catalysts with the α,β-unsaturated carbonyl compound are computed at semiempirical and ab-initio levels.
2. Qualitative Organic Analysis (
PDF)
A mixture of an aromatic acid and a neutral compound is provided. After their separation and purification, the two components are identified: the aromatic acid from its melting point (mp) and that of its amide and 1H NMR data; the neutral compound from its mp, IR, UV, NMR (1H, 13C, DEPT, gCOSY, HETCOR (HMQC), and GC-MS.
A crude preparation of a bacterial enzyme will be subjected to purification using various chromatographies. The resultant purified enzyme will be characterized, and its kinetic parameters will be determined. By comparing those for the wild-type and mutant enzymes, and by performing computer modeling of their structures with the substrate, the molecular rationale for the observed differences will be elucidated.
A student will select a chemical compound out of some 50 posted. Then (s)he will carry out a literature search concerning this compound assisted electronically by the Beilstein Commander 2002 and SciFinder2002 computer programs and literature sources available at the MIT libraries. After that, each student will present a 15-min oral report describing the structure, discovery, physical and chemical properties, and applications of the selected compound. Using the feedback obtained from the instructors and the fellow students during the oral presentation, the student will then prepare a 15-20 page written report (which also can be submitted to satisfy the MIT writing requirement).