STRUCTURE DETERMINATIONS OF -HYDROXY-5-IODOMETHYL-2,2-DIPHENYLTETRA-HYDROFURAN AND ROXY-2,2-DIPHENYLTETRAHYDRO-5-FURYL)METHYLAMMONIUM IODIDE

The conformation of the five-membered ring in muscarine-related compou nds was studied. The conformations observed in the two title compounds , (1) 5-iodomethyl-2,2-diphenyltetrahydrofuran-3-ol and (2) oxy-2,2-di phenyltetrahydro-5-furyl)methyl]ammonium iodide, are slightly differen t. In the iodomethyl compound the ring adopts an E3 envelope conformat ion in which the C atom connected to the hydroxy group is out of the b est plane through the remaining ring atoms. The ring adopts a 4T3 twis t conformation in the iodide salt with the C atom connected to the hyd roxy group and the methylene C atom out of the plane of the ring. In b oth cases, the hydroxy group is in an axial orientation. The puckering amplitudes are of the same magnitude (40.8 and 41.5-degrees, respecti vely). The crystal packing in the iodomethyl compound is stabilized by van der Waals contacts and that of the iodide salt by van der Waals c ontacts and electrostatic interactions. In the latter, a hydrogen bond is also observed between the hydroxy group and the iodide ion.