Cyclic organophosphorus compounds. Part 20. Structural correlations in the 2-amino-4-methyl-1,3,2-dioxaphosphinane series. X-Ray molecular structure of cis-2-t-butylamino-4-methyl-1,3,2-dioxaphosphinane 2-oxide
Abstract
The oxidation of cis-2-t-butylamino-4-methyl-1,3,2-dioxaphosphinane 2-selenide with hydrogen peroxide yields cis-2-t-butylamino-4-methyl-1,3,2-dioxaphosphinane 2-oxide. The oxide has been shown, by X-ray analysis, to exist in the chair form with the methyl and t-butylamino groups orientated equatorially, and the structure has been refined to R= 0.097. with a= 11.304(1), b= 9.702(1), c= 11.386(1)Å and β= 116.16(2)°. Predictions regarding the stereoretentive course of this oxidation procedure made elsewhere on the basis of n.m.r. data are thus confirmed. Further 13P chemical shift and 1J(31P,77Se) data now suggest that the correlation can be extended to include the 2-anilino and 2-benzylamino compounds.