Crystal and molecular structure of the monothioketal of 2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-one

The solid state conformation of the monothioketal of azabicyclic ketone has been elucidated using single crystal X-ray diffraction methods. The study reveals that the title molecule consists of two six-membered rings fused to gether in chair-chair conformation and a five membered spiro 1,3-oxathiolan e ring in envelope conformation. In the 3-azabicyclononane ring system, the equatorial dispositions of the phenyl groups and the orientations of the o xygen and sulphur atoms in axial and equatorial positions, respectively, ar e confirmed. The molecular conformation in the solid state is identical to that in solution previously proposed on the basis of spectroscopic studies.