Spring 2018 Name: Organic Chem 2 Due April 10-11 Spectroscopy Set IlI Hints and

Question

Spring 2018 Name: Organic Chem 2 Due April 10-11 Spectroscopy Set IlI Hints and Notes. On the next pages are four sets of spectral data. Note that all data is on one page that and note integrations are given under the NMR spectra. Also remember that thes ratios of the actual molecule. You may need lots of scratch paper for this. Be sure structure e numbers could possibly be r for this. to label the final Special information for 1'C NMR. These spectra show the three common ways of d NMR data. What you are used to, where each peak represents one C or equivalent bottom trace or "Broad Band". Above that is "Off -reso set of C atoms is the nance" which means the C atoms couples with any H atoms attached. So a -CH2 carbon will be a triplet. A methyl C will be a quartet, etc. is the DEPT trace. These DEPT are the kind that show only CH2 c arbons below the trace, and CH and CH3 are above the trace. Very importantly, remember that C having no H disappears in the carefully compare the three sets of data to figure out how many C you have, how many H and which are methylene or C without any H attached. DEPT. So are attached HINT for Exercise 010. Parent ion is 86. Also notice one C (about 45 ppm) that is completely non- detectable by 1H NMR. HINT for Exercise 011. Parent ion is 101. Use the 13C NMR to figure out how many C there are. Notice the expansion of the 'H NMR trace, although it is of limited use. That broad peak at 1.2 ppm will disappear if you stir this compound with D2O. HINT for Exercise 003. This structure is very simple if you figure out how to reconcile the MW with the proton integration given. Parent ion is 102. Hint for Exercise 068. Parent ion is 192. Carefully compare the broad band decoupled and the off resonance 1"C NMR spectra to discover a C that is not visible any other way, including on the 'H NMR.

Explanation / Answer

#003 Spectral analysis

IR shows peaks for,

3800-3000 cm-1 for sp3 -C-H stretch

1400-1500 cm-1 peaks for C-O stretch

1H NMR shows,

1.0 ppm (triplet, 6H) for CH3 next to CH2

1.7 ppm (multiplet, 4H) for CH2 between CH3 and CH2

3.5 ppm (quartet, 4H) for CH2 next to CH3

13C NMR shows,

CH2's at 24 ppm and 76 ppm

CH3 at 15 ppm

Mass showsm

M+ at 102

loss of CH3 gives m/z 87

loss of CH2CH2 gives m/z 59

loss of Oxygen gives m/z 43

So the structure of compound is,

CH3-CH2-CH2-O-CH2-CH2-CH3

dipropyl ether

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