Selected NOE Difference Spectra

Selected NOE Difference Spectra

upper trace: 300 MHz ¹H-NMR spectrum of 3a (d₆-DMSO)
lower trace: NOE difference spectrum of 3a; irradiation of CH₃-5 (2.78 ppm) 

 
upper trace: 300 MHz ¹H-NMR spectrum of 3a (d₆-DMSO)
lower trace: NOE difference spectrum of 3a; irradiation of CH₃-11 (3.46 ppm) 

 
upper trace: downfield region of the 300 MHz ¹H-NMR spectrum of 7 (d₆-DMSO)
lower trace: NOE difference spectrum of 7; irradiation of H-11: positive effects for H-10 and H-12, negative effect for H-9
("three-spin effect" [cf. D. Neuhaus and M. Williamson, 'The Nuclear Overhauser Effect in Structural and Conformational Analysis', VCH, New York - Weinheim - Cambridge, 1988, p. 81.]) 

Diels-Alder Reaction of Pyrano[3,4-b]indolones with Electron-Poor Pyridazinones: a New Pathway to Carbazole-Fused Pyridazines

Norbert Haider, Johann Käferböck, and Péter Mátyus

 http://merian.pch.univie.ac.at/~nhaider/echet98/spectra.htm