CYCLIC ORGANOPHOSPHORUS COMPOUNDS .9. 5-HALOGENOMETHYL-5-METHYL- AND 5,5-DIMETHYL-2-0X0-2-PIPERIDINO-1,3,2-DIOXAPHOSPHORINIANS

2α-Chloro(or bromo)-5β-chloromethyl(or bromomethyl)-5α- methyl-2β-oxo-1,3,2-dioxaphosphorinan reacts with piperidine to yield 5β-chloromethyl(or bromomethyl)-5α-methyl-2-oxo-2-piperidino-1,3,2- dioxaphosphorinan. N-Chloropiperidine reacts with 4-methyl-2,6,7-trioxa-1- phosphabioyclo[2,2,2]octane to give 5α-chloromethyl-5β-methyl- 2α-oxo-2β-piperidino-1,2,3-dioxaphosphorinan. The existence of the two conformers of 5,5-dimethyl-2-oxo-2-piperidino-1,3,2-dioxaphosphorinan is suggested.