Thesis-Final 03 June 2011 pdf - Jacobs University

Results and discussion Chapter 3
The 1 H-NMR spectrum shows that the reaction was achieved successfully. The non
equivalent protons of the two CH 2 group occurred at the beginning of the spectra. The
doublet of doublet at 2.12 ppm with large coupling constant J 14.9-12 Hz assigned to
6-H ax. This signal followed by multiplet at 2.18 ppm and assigned to 2-H ax due to
cross peaks at 1 H 1 H-COSY spectrum. The singlet at 2.29 ppm identified as
overlapping protons of the coumaroyl moiety. The singlet showed three protons
intensity and was assigned to H-41, H-42 and H-43. Another non equivalent protons
of CH 2 group occurred as two doublet of doublet. These two signals assigned to 6-H eq
and 2-H eq .The first part of CH 2 protons of Troc protecting group were identified at
4.57 and 4.78 ppm. The both protons found to be identical two doublets with large
coupling constant 11.9 Hz. Due to Karplus relationship, coupling constant indicates
that these two protons were trans to each other. .The quinide protons observed at 5.31,
5.78 and 5.80 ppm. The doublet of doublet at 5.31 ppm assigned to H-4 due to cross
peaks at 1 H 1 H-COSY spectrum. Then the two multiplets at 5.78 ppm and 5.80 ppm
were assigned to H-5 and H-3 after analysing cross peaks of 1 H 1 H-COSY and 1 H 13 C-
HMQC spectrums. The 1 H-NMR spectrum shows six doublets at 6.29, 6.32, 6.47,
7.58, 7.62 and 7.65 ppm with large coupling constants between J 10.5- 16 Hz. The
first three peaks 6.29, 6.32, 6.47 ppm were assigned to H-12, H-21 and H-30. These
signals were followed by multiplet at 6.96-7.14 ppm which was assigned to aromatic
protons. The second set of olefinic protons occurred again as three doublets just after
aromatic group protons between 7.02- 7.50 ppm. The signals at 7.57, 7.58 and 7.59
ppm were assigned to H-13, H-22 and H-31.
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