1. Examine the IR spectrum of cis-norbornene-5,6-endo-dicarboxylic anhydride, (Fig.48.8, pp. 630): what do the signals at 1750 cm-1 and 1838 cm-1 indicate?

2. Explain the following questions regarding the possible contamination of the final isolated product with dicyclopentadiene (the cyclopentadiene dimer).

a. Since "cracked" cyclopentadiene can spontaneously dimerize back to dicyclopentadiene, could the dimer be formed as an unwanted "by-product" during the experiment?

b. How does the experimental procedure minimize contamination of the final isolated (desired) product with this (undesired) "by-product"?