Chemistry 332 - Spring 1996
Elements of Organic Chemistry II
Homework, Chapter 14 - Carbohydrates
McMurry, pp 439-441:
Problems 14.24, 25, 28, 31, 33, 36, 37, 39, 42, 44
1. Construct a family tree for the D-ketoses up to the D-ketopentoses.
Your diagram should be patterned after the one shown in your text for the
D-aldoses (page 418).
The families of both D and L ketoses are shown below:
2. Write the Haworth and the chair form of beta-D-mannopyranose.
Compare the structures with those for beta-D-glucopyranose.
D-Mannose differs from D-glucose in just the 2-position. This is clear in
both the Haworth and the chair forms, where the only difference is the orientation
of the OH group at C-2.
3. Write all the steps in the mechanism by which open-chain D-ribose
is converted into a furanose hemiacetal form (beta-D-ribofuranose), followed
by conversion to an acetal form with methanol (methyl beta-D-ribofuranoside).
