William N. Setzer

Conformational analysis of mesocyclic polythioethers : Gas phase conformational analysis of five mesocyclic polythioethers using photoelectron spectroscopy

Abstract The helium I photoelectron spectra of the mesocyclic polythioethers 1,4-dithiacycloheptane (1,4-DTCH), 1,5-dithiacyclooctane (1,5-DTCO), 1,5-dithiacyclononane (1,5-DTCN), 1,4,7-trithiacyclononane (1,4,7-TTCN), and 1,6-dithiacyclodecane (1,6-DTCD) are reported. The conformations of these molecules in the gas phase are deduced from correlations of the observed spectra with semi-empirical MO calculations, as well as molecular mechanics analysis.

Highly diastereoselective oxidations of a thioether appended with a neighboring hydroxyl group

Abstract Highly diastereoselective oxidations of endo -alcohol 1 to the corresponding sulfoxides, the relative stereochemistries of these sulfoxides and that of an intermediary alkoxysulfonium salt determined by X-ray crystallographic analysis is reported.

CONFORMATIONAL ANALYSIS OF MESOCYCLIC POLYTHIOETHERS. CRYSTAL AND MOLECULAR STRUCTURES OF 1,4-DITHIACYCLOHEPTANE, 1,5-DITHIACYCLONONANE, AND 1,6-DITHIACYCLODECANE

Abstract The crystal and molecular structures of 1,4-dithiacycloheptane (1,4-DTCH), 1,5-dithiacyclononane (1,5-DTCN), and 1,6-dithiacyclodecane (1,6-DTCD) have been determined by single crystal X-ray studies. These compounds crystallize in the space groups P212121 (No. 19), P21/c (No. 14), and P21/n, respectively with a = 5.409(1), b = 10.883(2), c = 11.390(2) A, Z = 4; a = 9.600(4), b = 12.378(8), c = 7.904(3) A, /gb = 113.31(3)°, Z = 4; and a = 5.290(1), b = 12.853(3), c = 6.850(2) A, β = 93.39(2)°, Z = 2, respectively. The nonhydrogen atoms were located using direct methods and the hydrogen atoms were found by Fourier difference maps. Full-matrix least-squares refinement led to conventional R factors of 0.0459, 0.0558 and 0.0314, respectively. The conformations adopted by 1,4-DTCH, 1,5-DTCN and 1,6-DTCD, in the crystalline slate, are twist chair (C2 symmetry), twist boat chair (C2 symmetry), and boat chair boat (C2k symmetry), respectively. The transannular S-S distances are 3.583, 4.108 and 4.864 A, respectively.