Abstract: The title compound was synthesized and its crystal and molecular structure was determined by X-ray diffraction analysis with CuKa radiation. The crystal data are as follows; Or-thorhombic system, space group P2₁2₁2₁,a=0. 8365(3) nm, b=0. 8625(3) nm, c=2. 3512(2) nm, Z=4. The result of structure analysis shows there are three-membered ring structures in the molecular skeleton, the seven-membered ring is in a boat form and six-membered ring in a chair form including P(1) atom in the two rings, and the five-membered ring composed of carbon atoms is in an envelop form. In the molecule, S(1) is in an equatorial and O(1) in an axial position.Based on the appreciable anomalous scattering effect of Pand Satoms to the CuKa radiation, the absolute configuration of the molecule was established.

Key words: Diazaphosphabicyclo [3,2,1] octane, Synthesis, Absolute configuration