Learning Group Problem - Chapter 5
Stereochemistry
I. Streptomycin is an antibiotic that is especially useful against
penicillin-resistant bacteria. The structure of streptomycin is shown on
page 1087 of your text.
a) Identify all of the stereocenters in the structure of streptomycin.
b) Assign the appropriate R or S designation for the configuration of
each stereocenter in streptomycin.
II. Galactitol is one of the toxic compounds produced by the disease
galactosemia. Accumulation of high levels of galactitol causes the
formation of cataracts. The IUPAC name for galactitol is (2S, 3R, 4S,
5R)-1,2,3,4,5,6-hexahydroxyhexane.
a) Draw a three-dimensional structure for galactitol using dash-wedge
notation.
b) Draw the enantiomer of galactitol.
III. Cortisone is a natural steriod that can be isolated from the adrenal
cortex. It has antiinflammatory properties and is used to treat a variety
of disorders, including topical applications for common skin diseases.
The structure of cortisone is shown on page 1112 of your text.
a) Identify all of the stereocenters in cortisone.
b) Assign the appropriate R or S designation for the configuration of
each stereocenter in cortisone.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Craig B. Fryhle, Ph.D. Office 206-535-8314 FAX 206-536-5055
Associate Professor Email fryhle@u.washington.edu
Department of Chemistry URL http://rainier.chem.plu.edu/fryhle.html
Pacific Lutheran University
Tacoma, Washington 98447 ^ ^ ^ ^ ^ ^
^ ^^^ ^^^^^^^ ^ ^^^ ^^^^ ^^^ ^
^^^^^^^^^ ^^^^^^^^^ ^^^^^^^^^^^^^^^ ^^^^^^^^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^