Chemistry 332 - Spring 1996
Elements of Organic Chemistry II

Homework, Chapter 9 - Carbonyl Compounds

McMurry, pp 281 - 284:
Problems 9.20, 22-24, 26-32, 34-40, 44, 47


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 (H2O18) 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.