NITRATION BY OXIDES OF NITROGEN .7. PREPARATION OF DINITRATES AND POLYNITRATES BY RING-OPENING NITRATION OF OXETANES BY DINITROGEN PENTOXIDE (N2O5)

Ten oxetanes bearing various substituents were reacted with N2O5 in ch lorinated hydrocarbon solvents to yield 1,3-dinitrate esters (I) by ri ng-opening nitration. The yields ranged from 73 to 88% for di-/trinitr ates derived from oxetanes unsubstituted in the 2-position, to only 15 to 21% for oxetanes bearing such substituents. Although selective rin g cleavage of oxetanes bearing non-hydroxylic substituents (epoxy (oxi ranyl), spiro-oxetane and alkene) was not, in general, possible, selec tive nitration of hydroxyalkyloxetanes was achievable under the condit ions employed to yield nitrato-methyloxetanes useful as precursors for energetic polyethers. A semi-quantitative reactivity comparison with representative epoxides indicated that the reactivity of oxetanes towa rds N2O5 was lower, as expected on account of their lower ring strain.