N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
181
5.2 Alkenes
181
5.2.3 Allenes
1 H Chemical Shi fts and Coupling Constants (δ in ppm, J in Hz)
1 H Chemical Shifts and Coupling Constants of Monosubstituted Allenes
(δ in ppm, J in Hz)
Substituent R
H a
H b
J ab
Other
–H
4.67
4.67
-9.0
–CH 3
4.94
4.50
-6.7
CH 3 (c) 1.59, 3 J ac 7.2, 5 J bc 3.4
–CH 2 CH 3
5.03
4.55
-6.8
CH 2 (c) 1.95, 3 J ac 6.2, 5 J bc 3.5
–CH 2 Cl
5.4.3 4.92
-6.6
CH 2 (c) 4.11, 3 J ac 7.7, 5 J bc 2.2
–CH=CH 2
5.96
4.92
-6.6
CH (c) 6.31, 3 J ac 10.4, 5 J bc 1.1 a
–phenyl
5.91
4.92
–Cl
5.76
5.17
-6.1
–Br
5.85
4.83
-6.1
–I
5.63
4.48
-6.3
–OCH 3
6.77
5.48
-5.9
–COCH 3
5.77
5.25
-6.4
–C– – – N
4.97
5.04
–Si(CH 3 ) 3
4.92
4.31
–SiCl 3
5.35
4.92
-5.9
–SnCl 3
4.98
4.11
-7.2
a =CH 2 , H cis (d) 5.19, 4 J ad -0.8, 6 J bd -1.5, 3 J cd 17.2; CH 2 , H trans (e) 4.99, 4 J ae -0.9,
6 J be -1.8, 3 J ce 10.1, 2 J de 1.6
C C C
R
H
H
H
a
b
a
c
d
b
C C C
H
CH 3
H
H 3 C
C C C
H
H
H
H
a
c
b
4.67
5 J ab 3.2
6 J ac 0
3 J ad 6.8
4 J bd -6.4
2 J ab -9
4 J ac -6