Fourth seminar
1. What is the three-dimensional arrangement of substituents at the sp3, sp2 and sp hybridised carbon, nitrogen, oxygen and sulphur atoms? Hybridisation of phosphorus.
2. The conditions of being a chiral physical object (galaxies, hands, coils, screws, hands). Chiral molecules. Discuss chirality in differently substituted four-valent carbon atoms, allenes, biphenyls, supramolecular chemistry objects (DNA, peptides, and artificial structures).
3. Explain following terms and give examples thereof:
Constitutional (structural – skeletal, positional and functional) isomers
Conformer and Rotamer
Atropisomer
Geometrical isomers
5. Build (from plasticine or anything else) and bring the spatial model of bromochloroiodomethane and 2-hydroxypropanal (see below).
6. How many optical isomers possesses compound with one and more asymmetric carbon atoms?
7. The principle of drawing of the spatial projections of chiral compounds.
8. The principle of drawing compound formulas in Fisher projection.
9. The principle of assigning the absolute configuration of chiral atoms? – Cahn-Ingold-Prelog’s Rule. Please visit Wikipedia website of excellence (medal-awarded):
http://pl.wikipedia.org/wiki/Konfiguracja_absolutna
Unfortunately, the webpage is in Polish. It might be useful to enhance the English version of the website for the forthcoming ‘Macro’ generations.
10. Stereochemistry of cyclobutane, cyclopentane and cyclohexane rings. Conformers. Inversions of the ring. Mono-, di- and tri-substituted the above carbon-rings.
11. Assign the absolute configuration of:
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12. Draw in the spatial projections the R-enantiomers of:
phenylglycine (2-amino-2-phenylacetic acid)
1-chloro-2,3-dibromopropane
2-methylpentane
1,2-dihydroxypropane
3-amino-2-methylpropanol
2-butanol
13. Draw in the spatial projections the S-enantiomers of:
serine (2-amino-3-hydroxypropionic acid)
cysteine (2-amino-3-mercaptopropionic acid)
3-methoxy-2-methylpropanol
3-bromo-2-methyl-3-propylheptane
2-bromo-2-chloro-1-iodopropane
3-(N,N-dimethylamino)butanal
14. Transform the formulas from exercise 12 and 13 into the Fisher projections.
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