DR ANTHONY MELVIN CRASTO,WorldDrugTracker, helping millions, A 90 % paralysed man in action for you, I am suffering from transverse mylitis and bound to a wheel chair, With death on the horizon, nothing will not stop me except God................DR ANTHONY MELVIN CRASTO Ph.D ( ICT, Mumbai) , INDIA 25Yrs Exp. in the feld of Organic Chemistry,Working for GLENMARK GENERICS at Navi Mumbai, INDIA. Serving chemists around the world. Helping them with websites on Chemistry.Million hits on google, world acclamation from industry, academia, drug authorities for websites, blogs and educational contribution

Tuesday 25 November 2014

COSY, HETCOR, etc spectrum of Ethyl-2-butenoate.

Ethyl-2-butenoate
1H-NMR proton decoupled spectrum of Ethyl-2-butenoate in CDCl3.

1H-NMR proton coupled spectrum of Ethyl-2-butenoate in CDCl3.

13C-NMR proton decoupled spectrum of Ethyl-2-butenoate in CDCl3.

DEPT spectrum of Ethyl-2-butenoate

COSY spectra
  • The information on the H that are coupling with each other is obtained by looking at the peaks inside the grid.  These peaks are usually shown in a contour type format, like height intervals on a map.
  • In order to see where this information comes from, let’s consider an example shown below, the COSY of ethyl 2-butenoate 
  • First look at the peak marked A in the top left corner.  This peak indicates a coupling interaction between the H at 6.9 ppm and the H at 1.8 ppm.  This corresponds to the coupling of the CH3 group and the adjacent H on the alkene.
  • Similarly, the peak marked B indicates a coupling interaction between the H at 4.15 ppm and the H at 1.25 ppm.  This corresponds to the coupling of the CH2 and the CH3 in the ethyl group.
  • Notice that there are a second set of equivalent peaks, also marked A and Bon the other side of the diagonal.
COSY spectra of ethyl 2-butenoate
(COSY spectra recorded by D. Fox, Dept of Chemistry, University of Calgary on a Bruker Advance DRX-400 spectrometer)

HETCOR spectra
  • The information on how the H are C are matched is obtained by looking at the peaks inside the grid.  Again, these peaks are usually shown in a contour type format, like height intervals on a map.
  • In order to see where this information comes from, let’s consider an example shown below, the HETCOR of ethyl 2-butenoate.
  • First look at the peak marked A near the middle of the grid.  This peak indicates that the H at 4.1 ppm is attached to the C at 60 ppm.  This corresponds to the -OCH2- group.
  • Similarly, the peak marked B towards the top right in the grid indicates that the H at 1.85 ppm is attached to the C at17 ppm.  Since the H is a singlet, we know that this corresponds to the CH3- group attached to the carbonyl in the acid part of the ester and not the CH3- group attached to the -CH2- in the alcohol part of the ester.
  • Notice that the carbonyl group from the ester has no “match” since it has no H attached in this example.
HETCOR spectra of ethyl 2-butenoate
(HETCOR spectra recorded by D. Fox, Dept of Chemistry, University of Calgary on a Bruker Advance DRX-400 spectrometer)





Ethyl crotonate
Ethylcrotonate
1H spectrum
Ethylcrotonate
1H COSY
EthylcrotonateJres2D
1H homonuclear j-resolved 2D spectrum
EthylcrotonateT1
T1 analysis
EthylcrotonateT2
T2 analysis
EthylcrotonateC
13C spectrum
EthylcrotonateHETCOR
13C-1H HETCOR
EthylcrotonateHSQC
1H-13C HSQC
EthylcrotonateHMQC
1H-13C HMQC
EthylcrotonateHMBC
1H-13C HMBC


No comments:

Post a Comment