hrtest3bkey - Name THIRD HOUR TEST KEY 1(21 7 each In the...

Third Hour Test (b), Chemistry 302, Fall 2004, Page 1 of 7 pages
Name KEY
THIRD HOUR TEST
1. (21, 7 each) In the spaces provided below, give the correct IUPAC names for the compounds having each of the
following structures.
a. 7-chloro-3-cyano-5-cyclopentyl-2-ethoxy-6-oxohept-3-enoyl chloride
b. 5-amino-N-cyclohexyl-6-propoxy-N-propylcyclohepta-2,5-dienecarboxamide
c. 1-ethyl-4-mercaptobut-2-ynyl 4-ethyl-6-hydroxyhex-4-enoate
2.(6) Pravachol ® , for which the structure is shown to
the right, is one of the LDL (or “bad”) cholesterol
lowering drugs known as “statins.”
The final step in its synthesis, shown in simplified
form below , is reaction of NaOH with a lactone to
give the dihydroxycarboxylate product shown.
Write the steps in the mechanism that accounts for opening the lactone under the conditions shown.
REMEMBER: You may not add any other reagents. Be sure to show : (1) all intermediate structures that occur in the
course of the mechanism, (2) any resonance structures that play a role in the process, (3) what, if anything, is added or
lost at each step, and (4) all formal charges on the structures that you draw.

Third Hour Test (b), Chemistry 302, Fall 2004, Page 2 of 7 pages
3. (21) When synthesizing peptides, which are similar to proteins but contain fewer amino acids, one of the common first
step is to convert the carboxylic acid of an amino acid into a benzyl ester which can subsequently be removed by
hydrogenolysis when required by the synthesis. Below is shown preparation of the benzyl ester of alanine hydrochlor-
ide prior to its introduction into a peptide.
Write the steps in the mechanism that accounts for the indicated reaction under the conditions shown.
REMEMBER: You may not add any other reagents. Be sure to show : (1) all intermediate structures that occur in the
course of the mechanism, (2) any resonance structures that play a role in the process, (3) what, if anything, is added or
lost at each step, and (4) all formal charges on the structures that you draw.

Third Hour Test (b), Chemistry 302, Fall 2004, Page 3 of 7 pages
4. (14) Starting with methyl cyclopentanecarboxylate and 4-methyl-1-pentene as the only sources of carbon atoms
for the final product, show how to synthesize cyclopentylmethyl 3-methylbutanoate. You may use any other
needed reagents or solvents so long as they do not contribute carbon atoms to the product.