Structure Determination of Regioisomeric Fused Heterocycles by the Combined Use of 2D NMR Experiments and GIAO DFT 13C Chemical Shifts

The combined use of 2D NMR correlation experiments and GIAO DFT C-13 NMR chemical shift calculations has allowed a reliable and simple structural determination of regioisomeric heterocyclic systems that originate from the reactions of quinolinone or coumarin derivatives with hydroxylamine. In general, the proposed method may find application in the regioisomeric structural determination of heterocyclic compounds. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).