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