Crystal and molecular structures of 1R,3S,5S-3-(4-methylphenoxy)-3-thio-1,8,8-trimethyl-2,4,3-diazaphosphabicyclo[3.2.1]octane and its 1R,3R,5S-diastereoisomer

The crystal and molecular structures of 1R,3S,5S-3-(4-methylphenoxy)-3-thio-1,8,8-trimethyl-2,4,3-diazaphosphabicyclo[3.2.1]octane ((1) under bar) and its 1R,3R,5S-diastereoisomer ((2) under bar) have been determined by X-ray diffraction analysis. ($) under bar 1 crystallized in orthorhomic system with space group P2(1)2(1)2(1), a = 21.286(7), b = 9.009(1), c = 26.395(5) Angstrom; V = 5061.34 Angstrom(3), Z = 12, Dx = 1.222 g/cm(3). 2 crystallized also in ortherhomic system with space group P2(1)2(1)2(1), but a = 8.624(2), b = 8.374(1), c = 23.522(8) Angstrom; V = 1698.69 Angstrom(3), Z = 4, Dr = 1.214 g/cm(3). The geometric figures of the bicyclic skeletons in both diastereoisomers are similar with the six-membered phosphorus-containing rings in ''chaise lounge'' conformations. The 4-methylphenoxy group in (1) under bar is equatorial to the six-membered ring, but that in (2) under bar is axial. Three crystallographically independent molecules are present in the asymmetric unit of (1) under bar and have some significant differences in their corresponding torsion angles.