Étude des Paramètres de Résonance Magnétique Nucléaire et de la Stéréochimie de Thiono-2 R-2 Dithiaphosphorinanes-1,3,2

The ¹H, ¹³C and ³¹P n.m.r. spectra of eleven 2-R-2-thiono-1,3,2-dithiaphosphorinanes with various R groups attached to the phosphorus atom have been recorded and analysed. In the compounds where R=Cl, OMe or N, the molecule adopts a chair conformation with the R group axially oriented. When the molecule adopts a chair conformation with equatorially oriented R. In the case of the derivatives with R=phenyl, Me, N(Me)₂ or NHt-Bu, a chair–chair conformational equilibrium was observed. The hindered rotation about the P? N bond was also examined in the derivative with