Chem 313 Problem Set #2, 2010
1. Using detailed mechanisms, explain how you can determine whether or not ester
saponification happens through a tetrahedral intermediate (route A) or via aNdirect S 2
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mechanism (route B) using O labeled hydroxide ( OH ).
2. Explain why acid catalyzed ester hydrolysis is reversible, but saponification is not.
What conditions would you use to control the output of the acid catalyzed reaction?
H 3 /H2O
H2O + CH 3 CH 3H + H
OH /2 O
CH 3 CH 3H +
3. Outline how you would prepare the following amino acids using the Gabriel synthesis:
a. b. c. d.
O O O O
NH NH 2 NH 2 NH2
2 HO HO HO