Chem 335 - Winter 1999 - Organic Chemistry II
Portland State University - Dr. Carl C. Wamser


Chapter 15 Homework Answers

Brown & Foote, pages 581 - 592 :
Problems 15.14 - 22, 24 - 27, 31 - 35, 41, 44 - 52, 57 - 65


 1. Write complete names for each of the following:

a)

(R)-5-ethyl-8-hydroxyoctanal



b)

4,4-dimethyl-2,5-cyclohexadienone




2. Write a complete mechanism for the acid-catalyzed formation of the cyclic acetal between acetone and cis-1,2-cyclopentanediol.
Explain why an acetal is not formed with the trans isomer.

It is sterically difficult for the trans-1,2-diol to get both OH groups to connect to the same carbon of acetone.




3. Develop a synthetic sequence for 3-ethyl-3-hexanol that uses as organic starting materials only alcohols having four carbons or fewer.




4. Explain how acetone in the presence of radioactively-labelled water (H2O-18) slowly becomes radioactive itself.


The hydration reaction (addition of water as a nucleophile) does occur, although the equilibrium constant strongly favors acetone rather than 2,2-propanediol. Reversal of the reaction could eliminate either normal water or radioactive water.