1. Use through bond or through space interactions to assign structure
2D Spectroscopy
Use through bond or through space interactions to assign structure
COSY 1H 1H Correlation Spectroscopy
NOESY 1H 1H Nuclear Overhauser Enhancement Spectroscopy
HMQC 1H 13C Heteronuclear Multiple
(or HETCOR) Quantum Correlation
HMBC 1H 13C Heteronuclear Multiple
(or long range HMQC) Bond Correlation
through SPACE; the rest are through bond

2. 2-DIMENSIONAL SPECTRA: COSY
COSY-SQUARES

3. p. 195
COSY-CROSSHAIRS

4. p. 196
Example 1
shielding

5. p. 196

6. p. 196 10

7. Example 2
p. 197 4

8. p. 198 ?
13C NMR

9. HMQC (Heteronuclear Multiple Quantum Correlation)
experiments
1) Short range C—H (J ~ 135 Hz or more)
2) Long range 13C—C—C—H (J ~ 10 Hz)
you can set J to be whatever you want, to pick up say 2 bond couplings, but experiments are time consuming so we normally do the two above and that will solve most compounds.
HMBC is closely related to long range HMQC but gives the same information and is more tolerant of variation in the long range J value

10. p. 200 1H
13C
HMQC
13C-H 3

11. p. 200 1H
13C
13C-H 1

12. p. 200 1H
13C
13C-H 1

13. p. 200 1H
13C
13C-H
(J=135) ? 1

14. p. 200 D B C A
J=10Hz 6 2 4 5 3
13C-C-C-H
Missing to its own C in this case 1 D 6 1 5 2 4 C 3 A B

15. Long range HMQC (J = ~ 10Hz) OR HMBC
H—C—C—C 1

16. NOESY experiments pick up
CLOSE PHYSICAL CONTACT of non-coupled H’s
(through space rather than through bond)

17. When to expect NOESY Correlations
(p. 208 of manual)

18. BUT NOTE: NOESY spectra ALSO show COSY peaks,
Example 3, p. 201
COSY
NOESY
BUT NOTE: NOESY spectra ALSO show COSY peaks,
but in a different colour (here identified in green) 3

19. Example 4, p. 202
NOESY of penicillin
= COSY

20. Example 5, p. 203
If we can
assign HA
COSY
assigns others 5

21. If unable to assign HA NOESY COSY peaks p. 203 can assign this
but need to run COSY
first, to find new peaks
COSY peaks
run COSY first

22. Example 6, p. 204
EWG
so shifts o-protons
downfield 3

23. what multiplicities – unless the CH3 is there
EWG
Two places for –NO2 s d d
what multiplicities – unless the CH3 is there
our compound has one d most downfield (bottom p. 204)

24. p. 204 d
+ --CH3
NOESY
NOESY
Go to NOESY spectrum, 5

25. Yes, we see ONE NOESY between a CH3 and one H 1
p. 204
Yes, we see ONE NOESY between a CH3 and one H 1

26. p. 204
Must be one of these
NOESY
NOESY 5

27. multiplicity
p. 205 d d t t d d d t t d d d
4d + 2t
4d + 2t 3

28. Now think about couplings to thesed d t t d d d t t d d d
Now think about couplings to these d t t d
} we should be
able to see these
in the COSY d t d

29. This was the H with NOESY, we now look in COSY 1
p. 205
This was the H with NOESY, we now look in COSY 1

30. COSY of the aromatic region
p. 205
NOESY
d-t -t -d
d-d 7

31. Example 7, p. 206 from 2009 Final: Which isomer is correct?

32. NOESY Spectrum (COSY peaks suppressed), p. 207
Resonances at 9 and 10 ppm do NOT show any short range HMQC (i.e. they are the OH!)

33. Left with 1,2 or 5 as possible answers: go to COSY:
NOESY shows that OH has near H and there is another pair of H’s across ring fusion point that are close:
Rules out 3,4,7,8,9,10 and the fact that the one near the OH is a doublet rules out 6
Left with 1,2 or 5 as possible answers: go to COSY:
Note: there are 2 singlets!
Can only be 2
COSY of aromatic region

34. ASSIGNMENT 8