Chapter 15, Problem 46PP

Interpreting NMR spectra is a skill that often requires some amount of practice, which, in turn, necessitates access to a collection of NMR spectra. Beyond Labz Organic Synthesis and Organic Qualitative Analysis have spectral libraries containing over 700 1H NMR spectra. In this assignment, you will take advantage of this by first predicting the NMR spectra for two closely related compounds and then checking your predictions by looking up the actual spectra in the spectra library. After completing this assignment, you may wish to select other compounds for additional practice. 1. Write the IUPAC names for the following two structures: Question 2 Question 3 2. Predict the NMR spectra for each of these two compounds by listing, in the NMR tables below, the chemical shift, the splitting, and the number of hydrogens associated with each predicted peak. Sort the peaks from largest chemical shift to lowest. **Not all slots must be filled**

11:14 ... worksheets.beyondlabz.com 3. To check your predictions, click this link for Interpreting NMR Spectra 1. You will see a list of all the - compounds in the spectra library in alphabetical order by IUPAC name. Hovering over a name in the list will show the structure on the chalkboard. The four buttons on the top of the Spectra tab in the tray are used to select the different spectroscopic techniques for the selected compound. Make sure the NMR button has been selected. 4. Scroll through the list of names to find the names for the two compounds you have been given and click on the name to display the NMR spectrum for each. In the NMR tables below, list the chemical shift, the splitting, and the number of hydrogens associated with each peak for each compound. Compare your answers to your predictions. **Not all slots must be filled** Peak Chemical Shift (d) Multiplicity 1 2 3 4 5

О δα HO- H -Br δα HO-- + + -Br [B] 8+ HO- -Br δα न