N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
229
5.11 Carbonyl Compounds
229
1 H Chemical Shifts of Diketones (δ in ppm)
Long-Range Coupling in Ketones (|J| in Hz)
For fixed conformations, the coupling over the C=O group is often detectable for
W-arrangement of the coupling path.
5.11.3 Carboxylic Acids and Carboxylates
1 H Chemical Shifts (δ in ppm)
O
OH
H
H
H
COOH
H 3 C
O
O
O
O
O
O
O
O
2.34
3.24
7.96
7.87
| 4 J ab | 0–0.5
| 4 J ab | 1.0
3.62
For the enol form,
see Chapter 5.8.1
No W-arrangement
W-arrangement
2.17
3.0
O
R
R
O
H
H
Br
a
a
b
b
a
a
a
b
c
b
b
CDCl 3 DMSO D 2 O
a 8.05
8.13 8.26
b 10.85 12.50
CDCl 3 DMSO
a 2.10
1.91
b 11.51 11.91
CDCl 3 DMSO
a 1.16
1.00
b 2.39
2.21
c 10.35 11.90
COOH
COOH
COOH
COOH
COOH
11.51
12.2
11.96 1.23
8.12
7.45
7.62
11.49
2.35
11.88
12.09
1.68
1.62
0.93
1.39
1.21
1.00
1.06
2.31
2.18
2.43
5.95
6.15
6.53
12.8
(in D 2 O)
(in DMSO)
2.56
COOH
COONa
COOH
COOH
H COOH