Question

1. Examine the IR spectrum of cis-norbornene-5,6-endo-dicarboxylic anhydride, (Fig.48.8, pp. 630): (this is out of macroscale and microscale organic experiments 6e textbook can be googled to view) what do the signals at 1750 cm-1 and 1838 cm-1 indicate? (please include functional groups, structures, as much as possible so i can understand it) Thank you!

Answer 1

cis-norbornene-5,6-endo-dicarboxylic anhydride Anhydrides show IR peaks at 1760 and 1810 cm1. Also, the frequency of 5 membered ring can increase up to 30 cm1. Therefore, the peaks at 1750 cm1 and 1838 cm-1 indicate anhydride In addition, here there will be peak at 1100 cm due to -Co, 1600 cm,2850 cm1 - 3000 cm1 due to alkene