1H and13C NMR of bioactive isochromanylacetylarylhydrazone derivatives

Careful analysis of the 1H and 13C NMR spectra of a series of isochromanylacetylarylhydrazone derivatives indicated the diastereomeric selective character in the synthetic step used to obtain the derivatives employing acidic conditions during the condensation of the corresponding acylhydrazides with functionalized arylaldehydes. The relative configuration at C=N was characterized by extensive 1H and 13C NMR experiments. Homonuclear 1H×1H-COSY and heteronuclear 13C×1H-COSY-nJCH [n=1(1JCH); n=2 (2JCH) and 3 (3JCH), COLOC] 2D shift-correlated spectra, along with 1D PND and DEPT 13C NMR and NOE difference spectra (1H{1H} NOE) were also used in this deduction. © 1998 John Wiley & Sons, Ltd.