N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
5 1 H NMR Spectroscopy
5.1 Alkanes
5.1.1 Chemical Shifts
1 H Chemical Shifts and Coupling Constants (δ in ppm, J in Hz)
In long-chain alkanes, the methyl groups at δ ≈0.8
ppm typically show distorted triplets due to secondorder effects:
H 3 C
CH 3
CH 3
CH 3
0.86
0.91 3 J vic 7.4
1.33
0.90
0.89
1.74
3 J vic
6.8
0.88
1.27
1.27
CH 3
CH 3
0.23
2 J gem -12.4
CH 4
CH 3
CH 2
CH 3
a 0.91
b 1.31
3 J ab 7.3
2 J bb' -12.4
3 J bc 5.7
3 J bc' 8.5
CH 3
CH 2
CH 2
CH 3
CH 3
CH
H 3 C
CH 3
CH 3
CH 2
CH 2
CH 2
CH 3
© The Author(s), under exclusive license to Springer-Verlag GmbH, DE,
part of Springer Nature 2020
E. Pretsch et al., Structure Determination of Organic Compounds,
https://doi.org/10.1007/978-3-662-62439-5_5
167
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
5 1 H NMR Spectroscopy
5.1 Alkanes
5.1.1 Chemical Shifts
1 H Chemical Shifts and Coupling Constants (δ in ppm, J in Hz)
In long-chain alkanes, the methyl groups at δ ≈0.8
ppm typically show distorted triplets due to secondorder effects:
H 3 C
CH 3
CH 3
CH 3
0.86
0.91 3 J vic 7.4
1.33
0.90
0.89
1.74
3 J vic
6.8
0.88
1.27
1.27
CH 3
CH 3
0.23
2 J gem -12.4
CH 4
CH 3
CH 2
CH 3
a 0.91
b 1.31
3 J ab 7.3
2 J bb' -12.4
3 J bc 5.7
3 J bc' 8.5
CH 3
CH 2
CH 2
CH 3
CH 3
CH
H 3 C
CH 3
CH 3
CH 2
CH 2
CH 2
CH 3
© The Author(s), under exclusive license to Springer-Verlag GmbH, DE,
part of Springer Nature 2020
E. Pretsch et al., Structure Determination of Organic Compounds,
https://doi.org/10.1007/978-3-662-62439-5_5
167