Stable glucopyranosylpalladium complexes with cis-beta-hydrogen. A six-membered ring metallocycle with an oxygen donor ligand.

Two stable glucopyranosylpalladium complexes, chloro[1,3-dimethyl-5-(3,4,6-tri-O-acetyl-2-deoxy-alpha-D -arabinohexopyranosyl)-2,4(1H,3H)-pyrimidinedionnato] (triphenylphosphine)-palladium and the corresponding triphenylarsine analog, were studied using fast atom bombardment mass spectrometry, 1H, 13C and 31P nuclear magnetic resonance, UV and IR spectroscopy to establish structures for these complexes. The data obtained indicate that the pyranosyl ring is in a chair conformation in which palladium (C2'), acetoxy (C3' C4') and acetoxymethyl (C5') are equatorial and 1,3-dimethyl-2,4(1H,3H) pyrimidinedion-5-yl (C1') is axial. The palladium(II) ion is encompassed in a six-membered ring metallocycle in which C2' of the glucopyranosyl ring and the oxygen of the C4 carbonyl of the pyrimidinedionyl group occupy adjacent ligand sites.