THE MOLECULAR AND CRYSTAL-STRUCTURE OF PHOSPHABICYCLO-[2.2.1]HEPT-2-ENE-5,6-DICARBOXIMIDE

The structure of the title compound 1 has been determined by X-ray cry stallography analysis. The following crystal data were found: orthorho mbic, Pca2(1), a = 9.606(1), b = 16.356(1), c = 8.686(1) Angstrom. Bot h the phospholane and phospholene rings involved in the 7-phosphabicyc lo-[2.2.1] hept-2-ene system have almost regular envelope conformation s, and the cyclohexene ring has a significantly deformed boat conforma tion. The low value of the C-P-C angle, 84.2(2)degrees, reflects the s teric strain around the phosphorus bridge and may be responsible for t he reactivity of esters and amides derived from 1 in the O-insertion r eaction with m-chloro-perbenzoic acid. The dihedral angle between the plane of the benzene and succinimide rings is 82.4(2)degrees.