Six aryl diazoalkanephosphonates have been prepared and their proton and I3C n.m.r. spectra analyzed. The results suggest that the carbon bearing phosphorus (and the diazo-group) is essentially sp2 hybridized and that the dominant canonical form depends on the substitution of the aryl ring. Evidence is given for double bond character in the C-P bond.Six diazoalcanephosphonates d'aryle ont ete prepares et leurs spectres en r.m.n. du proton et du I3C ont ete analyses. Les rtsultats suggerent que le carbone porteur du groupe phosphore (et du groupe diazo) possede exclusivement une structure sp' hybridee et que la forme canonique dominante depend de la substitution sur le cycle aryle. Le caractere de double liaison dans le lien C-P a aussi Cte mis en evidence.[Traduit par le journal]Can.

The 13C n.m.r. spectrum of acetoxime has been obtained in five representative solvents and the chemical shifts of the three carbon atoms measured. The solvent effects on the chemical shifts are found to reflect specific solute-solvent interactions. The effect of deuteration of the u-protons on the chemical shift of the oximino carbon is also discussed.Le spectre r.m.n. de "C de I'acetoxime a ete obtenu dans cinq solvants judicieux, et les deplacements chimiques des trois atomes de carbone ont tte mesures. Les effets des solvants sur les deplacements chimiques rendent compte des interactions specifiques solute-solvant. I1 est egalement discute de I'influence d'une deuteration des protons en a sur le dtplacement chimique du carbone oximinique.

Eight 2,3-dideoxy-2-amino-3-nitrosugar derivatives have been obtained by an elimination-addition reaction on the a and B anorners of methyl-4,6-O-benzylidene-3-deoxy-3-nitro-gl~1copyranoside-2-acetate. P.m.r. is used to show that the conlpounds exist in the CE conformation. L3C.n~.r. data are presented for three anomeric pairs. Trends in the C-13 chemical shifts are found to be similar to those reported in other studies of carbohydrates. Exceptions in direction and magnitude of chcmical shift differences are discussed. Can.

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Die Titelverbindungen (III) wurden durch Umsetzung der Säurechloride (I) m′ Trimethylphosphit zu den Phosphonaten (IIa), deren Reaktion mit p‐Toluolsu fonsäurehydrazid und anschließende Zersetzung der Hydrazone durch Einwirkung von Na‐carbonat erhalten.