N
X
C
O
N
S
Hal
Solvents
Natural
Products
P Si
C
C
C C
C
C
246
5 1 H NMR
246
5 1 H NMR
H 2 N
O
–
O
HN
+
H 2 N
NH 2
N
H 2
+
HO
O
–
O
N
H 2
+
HO
OH
O
+
H 3 N
OH
O
HN
+
H 2 N
NH 2
N
H 2
+
OH
O
N
H 2
+
O
–
O
c
a
a
d
d
a
d
e
a
b
b
c
b
c
e
f
e
f
b
c
f
g
c
d
c, d
d
e
h
i
e
f
e
f
g
h
f
g
3 J ac 5.5
3 J bc 5.5
3 J ab
5.5
3 J bc
5.3*
3 J bd
5.3*
2 J cd ≈-15.0
3 J eg
6.5*
3 J fg
6.5*
3 J gh
5.3
3 J bc 6.1
3 J bd 6.1
3 J eg 6.9
3 J fg 6.9
3 J ab 8.2
3 J ac 10.4
2 J bc -15.0
3 J bd <2
3 J cd 4.2
3 J ab 8.0
3 J ac 10.2
2 J bc -14.5
3 J ab 8.6
3 J ac 6.4
2 J bc -13.5
3 J bd 7.6
3 J be 5.4
3 J cd 5.6
3 J ce 7.8
2 J de -13.0
3 J df 5.7
3 J dg 7.9
3 J ef 7.9
3 J eg 5.7
2 J fg -11.0
3.82
3.76
8.08
7.71
3.9*
3.9*
8.00
8.60
3.41
3.33
2.35
2.29
2.25
2.34
2.00
1.99
2.74
2.50
2.95
2.56
2.15
2.42
3.36
3.48
≈2.00
≈2.08
2.34
2.06
4.78
≈5
≈5
7.60
4.46
3.76
1.90
1.65
1.71
3.23
6.50
3.43
6.19
6.19
4.12
4.33
4.67*
(in TFA)
(in H 2 O, pH 7.0)
(in H 2 O, pH 7.0; * in D 2 O)
(in H 2 O, pH 7.0)
(in H 2 O, pH 7.0)
a
b
b
g
g
d
(in TFA)
* average
(in TFA)
* average
N
N
H
NH 3
+
O
O
–
N
N
H
NH 3
+
O
OH 3 J ab 6.4
4 J cd 1.4
3 J ab 7.7
3 J ac 5.0
2 J bc -15.0
4 J de ≈1
3.16
3.23
4.91
3.98
7.82
8.73
7.90
7.09
3.87
7.66
(in TFA)
a
a
d
e
b
c
b
c
d