First isolation and characterization of 1,2-oxaphosphetanes with three phenyl groups at the phosphorus atom in typical Wittig reaction using cyclopropylidenetriphenylphosphorane
stable crystals in the typicalWittigreaction of cyclopropylidenetriphenylphosphorane with activated carbonyl compounds. X-ray analysis of the oxaphosphetane showed that the phosphorus atom is at the center of a slightly distorted trigonal bipyramidal structure. Thermal decomposition of these oxaphosphetanes was carried out to give the starting carbonyl compounds and Wittigreaction products, olefins.