Thesis-Final 03 June 2011 pdf - Jacobs University

Results and discussion Chapter 3
122.25 ppm assigned to C-18, C-27 and C-36. The other aromatic group peak found at
129.51 ppm and assigned to C-15, C-25 and C-34. Similarly the peak at 129.58 ppm
assigned to C-19, C-28 and C-37. Further down of the 13 C-NMR spectrum another
two peak found to be belong to aromatic carbons The first one occurred at 131.85
ppm with one proton intensity and assigned to C-14 then the second peak occurred at
132.06 ppm as overlapping two carbon and assigned to C-23 and C-32. The last
carbons of aromatic group which are adjacent to oxygen atoms were found at 144.88,
144.94 ppm, 145.09 ppm and the signal assigned to as C-17, C-26 and C-35 due to
chemical shift considerations and 1 H 13 C-HMQC spectrum. The carbonyl carbons
occurred at down field of the 13 C-NMR spectrum. The first carbonayl carbons found
at 152.43, 165.67, 165.77, 165.84 ppm and assigned to C-8, C-11, C-20 and C-29.
Then these peaks followed by a singlet at 169.13 ppm with three carbon intensity
which proved that three signals were overlapping. Due to cross peaks at 1 H 13 C-
HMQC spectrum these carbons identified as carbonyls of acetayl group of coumaroyl
moiety C-38, C-39 and C-40. The signal at 169.97 assigned to C-7 as other spectral
data. The infrared spectrum shows strong signals at 2957 cm -1 (COOH), 1765, 1718
cm -1 (C=O), 1636 cm -1 (C Ar =C Ar ), 1205, 1165, 1107 cm -1 (C-O) as it was expected.
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40
60
80
F1 Chemical Shift (ppm)
100
120
140
160
8.0 7.5 7.0 6.5 6.0 5.5 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 132: 1 H 13 C-HMQC spectrum of (1R, 3R, 4S, 5R)-1-(β, β, β-trichloroethoxy
carbonyl)-3,4,5-tri-(acetyl p-coumaroyl) quinic acid
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