Assignment 6. Chem 3045x. Wednesday, October 18, 2000

This assignment is due, in class, on Friday, October 27, 2000

Chapter 7. Stereochemistry . Stereochemistry deals with the spatial arrangement of atoms in 3 dimensional space. Stereochemistry is concerned with both molecular structure and chemical reactivity. This chapter develops the important stereochemical ideas of chirality, a quality of an object that cannot be (in the geometric sense) superimposed upon its mirror image. Thus a chiral molecule possesses a structure which cannot be superimposed on its mirror image. The most common origin of chirality in organic molecules results from the occurrence of a stereogenic carbon which bears four different groups. We shall see how chirality is related to the observation of optical activity, the capacity of a substance to rotate the plane of polarized light. We will emphasize concepts rather than notation, but you must become familiar with the notation in the same way that you must be familiar with organic nomenclature.

Assignment for Chapter 7: Read: Sections 7.1-7.13, 7.16, 7.17

Problems: 7.1, 7.2, 7.3, 7.6, 7.7, 7.8, 7.13 7.14, 7.22-7.25, 7.29, 7.39, 7.40, 7.43, 7.44

Recommended: Visit the slide show on Chapter 6 on the web. An excellent Poon module on stereochemistry is on the computers in 211 Havemeyer: Use your Spartan software to make models and view them in 3D. Rotate them in space to be able to visualize them. View the following structures and figures which are available on your Spartan CD ROM:

Structures: 1,2-epoxypropane (p. 263): mirror images, methylethylamine (p. 290): mirror images, cholic acid (p. 283).

Figures:

Figure 7-1 (p. 261): FClBrIC mirror images

Figure 7-2 (p.262): ClF2HC mirror images

Figure 7-3 (p. 264): ClF2HC mirror images

Figure 7-4 (p. 264): 1,3-dichloro-1,3-dibromo cyclobutane

Figure 7-6 (p. 271): R or S ClF2HC

Figure 7-7 (p. 274): epoxidation of propene (animation)

Figure 7-8 (p. 275): Addition of HBr to E- and Z-2-butene (animation)

Figure 7-9 (p. 277): 2,3-dihydorxybutanoic acids. enantiomers and diastereomers

Figure 7-10 (p. 278): (2R,3R)-dihydroxybutanoic acid

Figure 7-11 (p. 280): 2,3-butanediol

Figure 7-12 (p. 280): meso-2,3-butanediol

Figure 7-13 (p. 283): cholic acid

Figure 7-17 (p. 289): isotactic polypropylene