PHOSPHORUS CONTENTS OF HETEROCYCLIC RING TRANSFORMATIONS .7. THE STRUCTURE OF PHOSPHOLENE-OXIDE DICHLOROCARBENE ADDUCTS - SYNTHESIS OF NEW 1-ALKOXY-DIHYDROPHOSPHININE-OXIDES

The structure of the products from the dichlorocyclopropanation reaction of a number of P-C and P-O-substituted phospholene-oxides is substantiated and characterized by X-ray analysis and NMR spectroscopy. An explanation is given for the outcome of the reactions yielding the trans-isomer solely or both of the two possible diastereoisomers. Thermolysis of the P-O-substituted adducts carried out in the presence of triethylamine affords the two double bond isomers of 1-alkoxy-dihydrophosphinine-oxides. The reactivity of the diastereoisomers for the adducts is briefly discussed.