Problem 2 - Predict a reasonable structure from the spectral information provide

Question

Problem 2 - Predict a reasonable structure from the spectral information provided below. As much as possible match the spectral information to the part of the structure that it explains. Show your work. IR Spectrum: Interpret as fully as possible frorm structure. Not every peak is interpretable. (units-em MS data exact mass MW- 324.2 M+1-20.00% M+2-2.9% 3340 1630 1380 1050 750 1735 2960-2850 1470 1230 4000 3500 3000 2500 2000 1500 1000 500 Proton NMR: interpret data (calculate chemical shifts to confirm they match actual values, N- # neighbors) 3.66 H,d 3.24 3H,s 2.0 1H,brd s 3.53 3.78 1H,dd 1.01 6Hd Jn7 J-12,7 3.91 Hdd J12,7 2.16 H,oct J-7 1.08 H.d 6.93 1H.t 4.03 1H,dd J-12.7 1.44 7.88 7.35 688 2.42 1H oct J#7 1H.q PPM 1"C and DEPT NMR: As much as possible match the "C peaks to carbons in your structure. Top spectrum-DEPT 135 NMR-CHs and CH appear (up) and CH2 appear, (down) 166.0 158.0 133.7 130.5 200 190 180 10 160 Middle spectrum- DEPT-90 BC NMR-oaly C-H appears (up) I90 180 170 160 150 140 130 120 110 100 90 80 " 60 so 40 30 20 1°1203 113.3 83.0 77.5 74.3 60 4 59.3 38 2 29.2 27.1 17.9 200 190 180 17016 150 140 130 120 110 10090 0 70 60 03 20 10 50 3 Botom spectrum-proton decoupled C NMR spectrum - shows all types of earbos proton decupled 'c NMR speetrum hows all ypes of garhorn 16 9x2 200 190 180 170 160 150 140 130 120 110 100 90 307 5 50 40 20 10

Explanation / Answer

To deduce the molecular form you can use the data in the 13C NMR spectrum, the 1H and the mass espectrum.

in the 13C that shows all the Carbons you can count there are 16 Carbons.

in the 1H you can use the data given for the integrations of each signal there are 23 H. (The big peak in 3.24 that integrate for 3H i think is of the solvent.

According to the IR signals you should have some Oxygen in your molecula.

Then from the mass we have that the MW of the compound is 324.2

then we can make a calculation.

16 C= 16(12.0107) = 192.17

23 H = 23(1.008) = 23.18

192.17+ 23.18= 215.354

then 324.2 - 215.354 = 108.84

we can assume that we have some O so to find and average relation we divide the result form the uma of the O

108.84/ 15.994 = 6.8

So you can asume there are 7 ore you can say there are 6 and try to calculate if there is another atom.

6(15.994) = 95.964

108.84-95.964 = 12.87 (like the uma of the C)

Then you can say that here are 17 C 23 H and 6 O

Hope this works for you!

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