assignment strategies using modern nmr …cic/nmr/nmrdatab/res_cmpd/pdfs/quin...using nmr have grown...
TRANSCRIPT
General methods for performing assignments, and verifying structuresusing NMR have grown to include now routine two-dimensional NMRexperiments.
The following slides show complete H and C assignments for quinine;identical methods were used to assign quinidine, which differs only in itsstereochemistry from quinine.
The assignment of quinine and quinidine was once considered a difficultassignment problem; it is reduced by 2D techniques and large magnets toat most a moderately difficult problem.
1H 1d, gDQCOSY, HSQC and gHMBC data are presented. These arefour of the most important modern NMR techniques used for chemicalassignments, and lack only in NOE data for comprising the majortechniques used by chemists for structure assignments.
20 mg of quinine in 0.5 ml benzene was used on our INOVA-600. The
sample amount could be reduced to ~1 mg in 80 l solvent in a 3mmShigemi tube without increasing experiment times unduly on our 600.
1 13
�
Pg. 1
Assignment Strategies Using Modern NMR Methods:Quinine in benzene-d6
Copyright@2005-2014 Charles G. Fry. All Rights Reserved.
ppm-0123456789
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
All assignment strategies should start withan examination of the 1H 1d spectrum.
1H 1d spectrumINOVA-600
quinine in C D6 6
Pg. 2
ppm7.27.47.67.88.08.28.48.6
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
1718
A useful starting point withquinine is the aromatic region,which is easily assigned from the1H 1d spectrum.
1H 1d spectrumINOVA-600
quinine in C D6 6
Pg. 3
ppm7.27.47.67.88.08.28.48.6
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
17
1821
1922
1H 1d spectrumINOVA-600
quinine in C D6 6
Pg.4
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
7.2
7.4
7.6
7.8
8.0
8.2
8.4
8.6
F1
(ppm)
7.2
7.4
7.6
7.8
8.0
8.2
8.4
8.6
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
For this portion ofthe assignments,cosy data (here inthe form of agDQCOSY) do notassist, except toverify what is easilyobserved in the 1H1d spectrum.
17
18
22
19
21
19�21�
22�19;21
�
17�18�
gDQCOSY600MHz
quinine in C D6 6
Pg. 5
# coupling dqcosy connections
Proton � (ppm) � type J (Hz) � (ppm) assign
17 8.60 1 d 4.53 7.64 18(17)
22 8.10 1 d 9.14 7.22 21(22)
18 7.64 1 d 4.55 8.60 17(18)
19 7.34 1 d 2.73 7.22 21(22)
21 7.22 1 dd 9.17 8.10 22(21)
2.67 7.34 19
dd(d?) <1 (.3)
When working with moderately to highly complex data sets, it isimperative to tabularize the data as you work.
The data must show consistency across all data sets. So far, only thesimple consistency between the aromatic assignments of the 1H 1dset and the gDQCOSY data is shown.
� �intg
Pg. 6
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
105
110
115
120
125
130
135
140
145
150
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
105
110
115
120
125
130
135
140
145
150
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Now 1H-13C HSQCdata is used toobtain carbonchemical shifts
. Thisdata has no value atthe moment, but willprove useful later.
andassignments
17
18
22
19
21
bz
HSQC 600MHzquinine in C D6 6
Pg. 7
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
105
110
115
120
125
130
135
140
145
150
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
105
110
115
120
125
130
135
140
145
150
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Now 1H-13C HSQCdata is used toobtain carbonchemical shifts
. Thisdata has no value atthe moment, but willprove useful later.
andassignments
Note how simple itis to assign thecarbons using the1H correlations.
17
18
22
19
21
bz
HSQC 600MHzquinine in C D6 6
Pg. 7
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
105
110
115
120
125
130
135
140
145
150
F2 (ppm)
7.07.27.47.67.88.08.28.48.6
F1
(ppm)
105
110
115
120
125
130
135
140
145
150
17
18
22
19
21
bz
Carbon assignments and chemical shifts can now be added to thetable from the HSQC.
Aside: We need ( / ) =8 times less concentration for an HSQC
than for a direct 13C 1d experiment (or can perform the experiment
at least 64 faster at the same concentration!). And we obtaininformation with the HSQC because of the 1H-13C correlations.
� �
�
H C3/2
more
# coupling dqcosy connections gHSQC
Proton (ppm) type J (Hz) (ppm) assign C(ppm)
17 8.60 1 d 4.53 7.64 18(17) 147.2
22 8.10 1 d 9.14 7.22 21(22) 132.2
18 7.64 1 d 4.55 8.60 17(18) 119.4
19 7.34 1 d 2.73 7.22 21(22) 102.1
21 7.22 1 dd 9.17 8.10 22(21) 122.7
2.67 7.34 19
dd(d?) <1 (.3)
� �intg �
Pg. 8
ppm4.64.74.84.95.05.15.25.35.45.55.65.75.8
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Now proceed through the rest of the 1H 1d,dqcosy and hsqc data in the same way.
An important assignment at this point is the11 proton (the solvent is benzene). The 11proton and carbon will link the quinolinesection of the molecule with the bicyclogroup, primarily via long-range 1H-13Ccouplings (using gHMBC data).
11
9
10
1H 1d spectrumINOVA-600
quinine in C D6 6
Pg. 9
F2 (ppm)
4.64.85.05.25.45.65.8
F1
(ppm)
80
90
100
110
120
130
140
F2 (ppm)
4.64.85.05.25.45.65.8
F1
(ppm)
80
90
100
110
120
130
140
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Again, the HSQCprovides simple 13Cassignments from the1H correlations.
In this case, it alsoprovides a simpleconfirmation (via 13Cchemical shift) of the11 proton assignment.
11
9
10
HSQC 600MHzquinine in C D6 6
Pg. 10
F2 (ppm)
2.02.53.03.54.04.55.05.5
F2 (ppm)
2.02.53.03.54.04.55.05.5
F1
(ppm)
2.5
3.0
3.5
4.0
4.5
5.0
5.5
F1
(ppm)
2.5
3.0
3.5
4.0
4.5
5.0
5.5
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The dqcosy provides easyentries into the aliphaticassignments.
The 11 proton correlateswith the 6a proton at 3.00ppm. Note the small
coupling 11 appears in the
1D as a singlet suggesting
the torsion angle is ~90 .
——
�
The 9 proton correlateswith the 3 proton at 1.97ppm.
11
3
9
6a
gDQCOSY600MHz
quinine in C D6 6
Pg. 11
# coupling dqcosy connections gHSQC
Proton (ppm) type J (Hz) (ppm) assign C(ppm)
17 8.60 1 d 4.53 7.64 18(17) 147.2
22 8.10 1 d 9.14 7.22 21(22) 132.2
18 7.64 1 d 4.55 8.60 17(18) 119.4
19 7.34 1 d 2.73 7.22 21(22) 102.1
21 7.22 1 dd 9.17 8.10 22(21) 122.7
2.67 7.34 19
dd(d?) <1 (.3)
11? 5.70 1 s 3.0(wk) 6a? 71.8
s(d?) ~1
9a 5.35 1 ddd 16.99 4.80 10b 142.4
10.26 4.73 10a
7.89 1.97 3?
10b 4.80 1 dt 17.07 5.35 9a 115
1.28 4.73 10a
1.28 1.97 3?
10a 4.73 1 dt 10.30 5.35 9a 115
0.80 4.80 10b
0.80 1.97 3?
It is vital to continue to tabulate the data. Question marks can beinserted to show uncertain assignments. It is important to indicateweak correlations in the dqcosy and hsqc in the table.
� �intg �
Pg. 12
1.0
7
3.1
8
0.9
1
1.0
2
1.0
7
2.1
0
2.0
7
1.0
3
1.0
0
2.0
4
3.5 3.0 2.5 2.0 1.5 PPM
Standard practices such as countingprotons via integrals must not beignored in the “glitz” of using 2Dtechniques.
Nine protons have already beenassigned. All protons should beobserved, with the possible exception
of the OH group. 15 more areintegrated, exactly the number
expected the
including OH proton.This proton is therefore present(likely at 3.29ppm).
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Pg. 13
ppm2.42.52.62.72.82.93.03.13.23.33.43.53.63.73.8
Closer inspection of the aliphatic region ofthe 1H 1d spectrum shows that most of theprotons are resolved at 600MHz, but regionssuch as 2.4 to 2.5 ppm may be troublesome.
The multiplet at 3.0 ppm has already beententatively assigned to the 6a proton via thecoupling to 11 from the dqcosy spectrum.
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
6a?
OH?2
protons
-OCH3
Pg. 14
ppm1.11.21.31.41.51.61.71.81.92.0
One of the protons at 1.97 ppm (it has anintegral of 2) is already tentatively assignedto the 3 proton, from coupling to the 9proton in the dqcosy spectrum. The 1.25 to1.18 ppm region also has two overlappingprotons.
dqcosy should provide most of theassignments, if we keep in mind that protonscloser to the 1 nitrogen will be pushed tohigher frequencies. Thus, the 5, 4 and 8protons are likely to be in the low frequency(upfield) region.
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
2protons
3 +?
Pg. 15
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
A key question is whereto start (entry points). Theobvious answer here is the6a and 3 protons. The 3proton is messy, as anotherunknown proton isoverlapping, so startwith 6a at 3.00ppm.
Other than 11, 6a willstrongly couple only tothe 5a and 5b protons.One of these isoverlapping with the3 proton.
6a?
5a?
5b?
gDQCOSY600MHz
quinine in C D6 6
Pg. 16
OH
-OCH3
3+?
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
An expansionof the 3,5aregion at 1.96ppm showsthat 5a is onthe low-freqside of themultiplet.
In the table,3 can beassigned to1.960 ppm,and 5a to1.957 ppm(keeping in
mind thatcan beimprovedlater).
�
5a?
F2 (ppm)
1.96
F1
(ppm)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
F2 (ppm)
1.96
F1
(ppm)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
gDQCOSY600MHz
quinine in C D6 6
6a 5a�
Pg. 17
3?
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
A number ofprotons can beassigned withthe 3 dqcosycorrelations:
1.59 ppm (wk)2.47 ppm2.81 ppm4.73 ppm (wk)4.80 ppm (wk)
Although someof these mayseem suspect,they can beincluded ifverification ismade withother data ata later time.
F2 (ppm)
1.96
F1
(ppm)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
F2 (ppm)
1.96
F1
(ppm)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
gDQCOSY600MHz
quinine in C D6 6
3 9�
Pg. 18
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
Similarly, anexpansion ofthe 5b? regionshows two setsof correlationsthat can betentativelyassigned. Thelow-freq cross-peaks areassigned to 5b:
1.59 ppm1.96 ppm3.00 ppm
leaving 1.80,2.44 and 3.79ppm peakscorrelating tothe otherproton.
5b?
F2 (ppm)
1.20
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.20
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
gDQCOSY600MHz
quinine in C D6 6
Pg. 19
# coupling dqcosy connections gHSQC
Proton � (ppm) � type J (Hz) � (ppm) assign �C(ppm)
11? 5.70 1 s 3.0(wk) 6a? 71.8
s(d?) ~1
9a 5.35 1 ddd 16.99 4.80 10b 142.4
10.26 4.73 10a
7.89 1.97 3?
10b 4.80 1 dt 17.07 5.35 9a 115
1.28 4.73 10a
1.28 1.97 3?
10a 4.73 1 dt 10.30 5.35 9a 115
0.80 4.80 10b
0.80 1.97 3?
24 3.64 3 s none 56.1
s(d?) 0.48
-OH? 3.28 1 s none
6a? 3.00 1 t 8.78 5.7(wk) 11? 60.7
1.97 5a?
1.22 5b?
3? 1.97 1 m 2.40 2.476 2b? 40.7
2.81 2a?
5.35 9a
4.80(wk) 10b
4.73(wk) 10a
1.59(wk) 4?
5a? 1.96(hsqc) 1 ~7 3.00 6a? 20.5
1.22 5b?
5b? 1.22u 1 m 3.00 1.59 4? 20.5
1.96 5a?
3.00 6a
The table nowcontains a lotof data,includingcarbonassignmentsfrom theHSQC on thenext page.
Many of theassignmentsare tentativeat this point;they needmore data forconfirmation.
� �intg �
Pg.20
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
HSQC provides asimple method of
identifying CH2groups. Four groupsare expected in thealiphatic region:
5, 8, 7, and 2
with only 10 outsidethis region.
��������
HSQC 600MHzquinine in C D6 6
Pg. 21
F2 (ppm)
123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
123456789
F1
(ppm)
20
40
60
80
100
120
140
160
00
This plot shows an HSQCdata set obtained with theparameter:
giving a DEPT-135appearance to the data.The four aliphaticCH2 groups plus the vinylmethylene are observed asinverted in intensitycompared to the othercorrelations .
For quinine, mult=2 data isnot needed; it involves lossin sensitivity, and shouldnot be run, unless requiredand the conc is high.
mult=2
(red)
(blue)
HSQCAD is a newexperiment that greatlyimproves data quality inmult=2 spectra.
HSQC 600MHzquinine in C D6 6
Pg. 22
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
HSQC also displays theresolution in protonchemical shifts observedin the dqcosy spectra,
.
The differences areclear at ~2.42ppm and~1.97ppm, but not so at~1.22ppm. More points
in the direct F2dimension may haveprovided sufficientresolution at 1.22ppm.
�
( )
which is not obtained inthe 1H 1d spectra
np
HSQC 600MHzquinine in C D6 6
Pg. 23
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The 3 and 5aassignments are now
confirmed via 13C .�
3 was initially assignedvia dqcosy correlationwith the 9 proton.
5a was initiallyassigned via dqcosycorrelation with the 6aproton.
3
5a
HSQC 600MHzquinine in C D6 6
Pg. 24
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
5b is confirmed bythe carbon chemicalshift (being identicalto 5a).
The assignment of 5bbeing on the low-frequency side of the1.22ppm multiplet isstill tentative.
3
5a 5b
HSQC 600MHzquinine in C D6 6
Pg. 25
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
6a was assigned via thedqcosy correlation with
11. The last >CHproton left is 4, whichcan now be unambi-guously assigned to the1.59ppm multiplet.
This multiplet is narrow,esp. for a proton that hasmany 3-bond neighbors:the dqcosy shows threeweak correlations to 3, 5band 8a. The torsion
angles are all close to 90 .�
3
6a
4
HSQC 600MHzquinine in C D6 6
Pg. 26
OH
-OCH3
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
These assignments leavethree CH2 groupsunassigned. The CH2 at
13C 27ppm and
1H 1.80,1.22ppm
can be safely assigned tothe 8 carbon and 8a,8bprotons from chemicalshift considerations.
This assignment can beconfirmed, and the othertwo CH2’s assigned usingthe dqcosy data.
3
5a 5b
6a
4
8b8a
HSQC 600MHzquinine in C D6 6
Pg. 27
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The 8 protons shouldcorrelate to the 7 protons,as well as the 4 proton.
The 8a correlationsare shown:
to 8bto 4to 7bto 7a
6a
5a3 4
8a7b
7a5b
8b
gDQCOSY600MHz
quinine in C D6 6
Pg. 28
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The 8b correlations areshown:to 8ato 4 (+ 5b correl.)to 7bto 7a
The 5b correlations areshown in light gray.
6a
5a3 4
8a7b
7a5b
8b
gDQCOSY600MHz
quinine in C D6 6
?
Pg. 29
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The protons 2a and 2bshould correlate only witheach other and proton 3.
Proton 2a is a dd; wecould have used thismultiplet as a starting(entry) point in theassignments.
2b correlations are shown:to 2ato 3
6a
5a3 4
8a
7b
7a2a
2b 5b8b
gDQCOSY600MHz
quinine in C D6 6
Pg. 30
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
6a
5a3 4 5b
8b8a
7b
7a2a
2b
2a correlations are shown:
and
finishing all protonassignments.
The keys to thisprocedure were carefultabularization of thedata and the use ofmultiple sets of data.
to 2b to 3
gDQCOSY600MHz
quinine in C D6 6
Pg. 31
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The HSQC datafinishes all protonated-carbon assignments.The 7 and 3 carbonscould have been safelyassigned based onchemical shift.
gDQCOSY600MHz
quinine in C D6 6
Pg. 32
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
3
5a 5b
6a
4
8b8a
7b7a
2b2a
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
gHMBC is not neededfor 1H quinineassignments, but
gHMBC provides theonly method forquaternary 13Cassignments of lowconc samples.
gDQCOSY600MHz
quinine in C D6 6
Pg. 32
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
F2 (ppm)
1.21.62.02.42.83.23.6
F1
(ppm)
25
30
35
40
45
50
55
60
3
5a 5b
6a
4
8b8a
7b7a
2b2a
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
gHMBC produces aseeming maze of data,but with carefulinspection andtabularization of thedata, this can be thekey data set fordifficult assignments.
gHMBC 600MHzquinine in C D6 6
Pg. 33
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
gHMBC providesthe best method formaking quaternarycarbons assignments(but relying on thepresence of long-range1H-13C J-couplings).
gHMBC 600MHzquinine in C D6 6
Pg. 34
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Quaternary 13Cassignments:
The hsqc data are shownin red.
Look for carbon chemicalshifts missing an HSQCcorrelation.
Only four quaternarycarbons exist in quinine.
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
gHMBC 600MHzquinine in C D6 6
24
Pg. 35
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
Quaternary 13Cassignments:
The four quaternarycarbons are found at:
ppm144.9 ppm149.8 ppm
ppm
127.5
159.1
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
gHMBC 600MHzquinine in C D6 6
24
Pg. 35
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The quaternary carbon at159.1 ppm has a correlationto the 24 methyl protons;this carbon must be the 20carbon.
The strongest othercorrelation is to proton 22,a 3-bond J . Correlations
to protons 19 and 21 aremoderately strong; theweak apparent couplingto proton 18 cannot be
trusted (5-bond)
CH
.
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C20
gHMBC 600MHzquinine in C D6 6
24
Pg. 36
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The C20 assignmentdisplays a general and veryuseful aspect of aromaticJ values:
J range 1 to 4 Hz
J range 7 to 10 Hz.
CH
CH
CH
2
3
3-bond C-H gHMBCcorrelations in aromaticsystems will always bestronger than 2-bondcorrelations (for jnxh=8).
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C20
gHMBC 600MHzquinine in C D6 6
24
Pg. 37
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The next quaternary is at149.8 ppm, withcorrelations to the:
17 proton22 proton (wk)18 proton (wk)19 proton11 proton
This must be C13;C14 would not correlate(strongly anyway) to H17,and the correlation C14 toH22 would be strong.
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C13
gHMBC 600MHzquinine in C D6 6
Pg. 38
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C15
The next quaternary isat 144.9 ppm, withcorrelations to the:
17 proton22 proton (wk)19 proton21 proton
This must be C15,because of the strong3-bond aromaticcorrelations.
gHMBC 600MHzquinine in C D6 6
Pg. 39
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C14
Last is C14; we shouldexpect H22 and H18 togive strong (3-bond)correlations. H11 shouldshow a correlation, but ofunpredictable strength.
17 is weak22 strong18 strong21 is weak11 is moderate
gHMBC 600MHzquinine in C D6 6
Pg. 40
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
A look at the 6 carbonshows correlations to:
18 proton (wk)11 proton2a proton2b proton (7b?)5a proton (low-freq side)4 proton5b proton
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C6a
?
gHMBC 600MHzquinine in C D6 6
Pg. 41
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
F2 (ppm)
0123456789
F1
(ppm)
20
40
60
80
100
120
140
160
14
15
19
22
20
21
18
17
13
N16
11
6
5
N1
4
2
3
9
CH2108
7
OH12
O23
CH324 H
6a
The 9 carbon showscorrelations to:
10 protons2a proton2b proton (high-freq side)4 proton (wk)3 proton (wk)5a and/or 8a (wk)
6a 5a
3 45b8b
8a7b
7a 2a2b10
9
111921
18
2217
C9
gHMBC 600MHzquinine in C D6 6
Pg. 42