H-NMR, C-NMR
1 H NMR (CDCl3, 500 MHz) δ 5.73 (d, J = 0.8 Hz, 1H), 5.50 (dd, J = 10.1, 2.5 Hz, 1H), 5.45 (ddd, J = 9.9, 5.0, 1.7 Hz, 1H), 4.26 (d, J = 11.0 Hz, 1H), 3.97 (d, J = 10.7 Hz, 1H), 3.95 (d, J = 10.6 Hz, 1H), 3.75 (d, J = 1.2 Hz, 1H), 3.40 (dd, J = 11.1, 1.3 Hz, 1H), 2.66 – 2.42 (m, 1H), 2.43 – 2.12 (m, 4H), 1.91 (ddd, J = 17.3, 5.1, 0.9 Hz, 1H), 1.31 (s, 3H), 1.16 (s, 3H);
Intermediate 15:
Shift |
Hydrogen(s) |
Rationale |
5.73 s |
n |
Attached to an sp2 carbon so high shift. |
5.50 d |
a |
Coupled with b, high shift from sp2 carbon. |
5.45 ddd |
b |
It is one of two Hs that has 3 distinct neighbors, and is part of an alkene |
4.26 d |
f |
Ether doublet coupled to g. |
3.97 d |
i |
Ether, doublet, coupled to h. |
3.95 d |
h |
Ether, doublet, coupled to i. |
3.75 d |
g |
Ether, doublet coupled to f. |
3.40 dd |
c |
Coupled to c and b. |
2.66-2.42 m |
e |
no singlets, so probably long bond coupling with several neighbors |
2.43-2.12 m (4H) |
j,k,l,m |
3 couplings for each hydrogen, 4 very close together |
1.91 dd |
d |
coupled to c and b. |
1.31 s (3H) |
Me |
CH3 group, closer to O |
1.16 s (3H) |
Me |
CH3 group |
H-NMR 16:
H NMR (500 MHz, CDCl3) δ 5.58 (t, J = 8.4 Hz, 1H), 5.41 (d, J = 10.4 Hz, 1H), 5.34 (dd, J = 10.4, 4.2 Hz, 1H), 4.31 (s, 1H), 3.91 (d, J = 12.4 Hz, 1H), 3.71 (d, J = 12.4 Hz, 1H), 3.64 (d, J = 12.4 Hz, 1H), 3.57 (d, J = 19.1 Hz, 1H), 3.46 (d, J = 12.4 Hz, 1H), 2.86 (d, J = 19.1 Hz, 1H), 2.75 (ddd, J = 14.0, 10.1, 4.1 Hz, 1H), 2.55 (m, 1H), 2.23 (dd, J = 13.7, 8.0 Hz, 1H), 2.00 (d, J = 18.0 Hz, 1H), 1.97 (d, J = 15.0 Hz, 1H), 1.60-1.64 (m, 1H), 1.52 (dd, J = 17.7, 5.1 Hz, 1H), 1.21 (s, 6H);
Shift |
Hydrogen(s) |
Rationale |
5.58 t |
m |
high shift from nitro, couples with k? |
5.41 d |
i2 |
high shift ether, coupled to i1 |
5.34 dd |
i1 |
high shift ether, coupled to i2 / j |
4.31 s |
e |
no neighbors, ether so high shift |
3.91 d |
h1 |
doublet pair, high shift ether |
3.71 d |
h2 |
doublet pair, high shift ether |
3.64 d |
g1 |
doublet pair, high shift etther |
3.57 d |
g2 |
doublet pair, high shift ether |
3.46 d |
k1 |
doublet pair, close to nitro and ketone |
2.86 d |
k2 |
doublet pair, close to nitro and ketone |
2.75 ddd |
c |
only one that is ddd |
2.55 m |
j |
most electronegative multiplet |
2.23 dd |
d1 |
pair coupled to each other and c |
2.00 d |
l1 |
least electronegative pair, ~l2 |
1.97 d |
l2 |
least electronegative pair, ~l1 |
1.60-1.64 m |
b |
has complex splitting to several hydrogens |
1.52 dd |
d2 |
pair coupled to each other and c |
1.21 s (6H) |
a&f |
only group of 6 equiv hydrogen |