Thesis-Final 03 June 2011 pdf - Jacobs University

Results and discussion Chapter 3
The 13 C-NMR shows thirteen signals, which are consistent with the 1 H-NMR
spectrum. The very first two signals at 24.36 and 28.14 ppm are methyl carbons which
correspond to C-12 and C-13. The two methylene carbons occurred at 34.48 ppm and
38.63 ppm was assigned to C-2 and C-6. The typical carbons of quinide found at
66.73, 68.21 and 72.30 ppm was assigned to C-3, C-4 and C-5. The two Troc group
carbons found at 74.65 and 93.45 ppm. The signal at 74.65 ppm assigned to CH 2
carbon of the Troc group and the signal at 93.45 ppm was assigned to another carbon
of Troc group, which is adjacent to chlorine atoms therefore due to the electronegative
effect of the chlorine group this carbon occurred in downfiled compared to the
methylene carbon of the Troc group.
The typical C-1 quinide carbon was found at 82.39 ppm. The quaternary acetal which
hasn’t got any hydrogen attached to it appeared at 109.14 ppm and assigned to C-11.
Two peaks of the carbonyl group were found downfiled at 152.38 and 170.78 ppm.
Due to electronegative effect the peak at 152.38 ppm was assigned to C-8 carbon and
the peak at 170.78 ppm was assigned to C-7 carbons. The Infrared spectrum shows
absorptions for the carbonyl ester at 1807, 1767 cm -1 .
20
40
60
80
F1 Chemical Shift (ppm)
100
120
140
160
5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0
F2 Chemical Shift (ppm)
Figure 50: 1 H 13 C-HMQC spectrum of 1-(β, β, β-trichloroethoxycarbonyl)-3, 4-Oisopropylidene
quinide, (47)
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