MUSCARINIC ANTAGONIST - ABICYCLO[3.2.1]OCTANE-3,2'-1',3'-DIOXOLANE)-4'-ONE IODIDE

The molecular structure of the title compound, C23H26NO3+.I-, BVT44Me, has been compared to that of the related compound 8,8-dimethyl-3,3-di phenyl-1,4-dioxa-8-azoniaspiro [4.5]decan-2-one iodide, spiro-DAMP [Sa batino, Recanatini, Tumiatti & Melchiorre (1994), Acta Cryst. C50, 640 -645]. The dioxolane ring adopts an envelope conformation in spiro-DAM P (the ether O atom being out of the plane of the ring) and a twist co nformation in BVT44Me (the ether O and the C atom at the spiro positio n being out of the plane of the ring). This makes the spatial orientat ions of the substituents of the dioxolane ring slightly different. The crystal packing in BVT44Me is stabilized by electrostatic interaction s and van der Waals contacts. Charge-charge interactions place the I- ion close to the quaternary ammonium group. These interactions may be classified as hydrogen bonds (CH ... I).