PHOSPHORYLATED INDOLIZINES

Preparative methods of synthesis of 1- and 3-phosphino-indolizines by interaction between 2-substituted indolizines with phosphorus(III) hal ogenides in the presence of bases have been developed. It was found th at originally this reaction results in the formation of 1-phosphino-in dolizines which then undergo izomerization into 3-phosphino isomers. O ne, two, or three indolizine substituents can be consecutively attache d to the phosphorus atom. New methods of syntheses of 1,3-diphosphino- indolizines have been developed.