Organic Chemistry II
	Professor Carl C. Wamser
Chem 335 - Winter Term	Quiz 13

1. (2 points)  How many different peaks would be expected in the C-13 NMR spectrum (decoupled) for 1,5-dimethylnaphthalene? 
What is its molecular formula and IHD?

6 different C-13 peaks

C12H12 - IHD = 7

2.  (2 points)  Explain how you could distinguish between the ortho and para isomers below.

using H-NMR:

para - two singlets, one for the CH3 and one for the four equivalent aryl Hs

ortho - one singlet for the CH3 groups and two doublets for the aryl Hs

using C-13 NMR:

para - total of 3 peaks

ortho - total of 4 peaks

3.  (6 points)  Identify the unknown compound that gives the following spectral data.  Indicate what information you gain from each bit of data.

molecular formula - C5H9BrO2          

IHD  = 1

mass spec - m/z = 180, 182 (approximately equal intensities)

molecule contains one Br

infrared - strong peak at 1740 cm-1

molecule contains a C=O

H-NMR -
         1.3 ppm, 3H, triplet

CH3 with 2 neighbors

         1.8 ppm, 3H, doublet

CH3 with one neighbor

         4.2 ppm, 2H, quartet

CH2 with 3 neighbors, next to an electronegative element

         4.4 ppm, 1H, quartet

CH with 3 neighbors, next to an electronegative element