Cage peroxides having planar bridgehead nitrogen atoms

Three new cage peroxides, 1,6-diaza-3,4,8,9-tetraoxabicyclo[4.4.2]dodecane (3a),1,6-diaza-3,4,8,9-tetraoxa-11-methylbicyclo[4.4.2]dodecane (3b), and 1 ,6-diaza-3,4,8,9-tetraoxatricyclo[4.4.2.4(11,12)]hexadecane (4), have been prepared by reaction of 1,2-diaminoethane, 1,2-diaminopropane, and trans-1, 2-diaminocyclohexane, respectively, with formaldehyde and hydrogen peroxide in aqueous acidic solution. Their structures have been established by X-ra y diffraction, and show the bridgehead nitrogen atoms to be predominantly s p(2) hybridized. The structures accord with H-1 and C-13 NMR spectra. Varia ble temperature NMR studies show that the diperoxide 3a begins to undergo r apid inversion (on the NMR time scale) at about 303 K; up to 370 K the dipe roxides 3b and 4 show no conformational change.