M. Hemmerling et al., MULTISTEP REDOX SYSTEMS, LXVI - AN UNCOMMON DERIVATIVE OF 4H-THIOPYRAN-4-ONE - 4H,8H-THIOPYRANO[3,2-B]THIOPYRAN-4,8-DIONE - SYNTHESIS, REDOX PROPERTIES, AND CALCULATIONS, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (9), 1998, pp. 1989-1996
Starting from tetrahydrothiopyran-4-one (4d) a rational eight-step syn
thesis of 3a has been developed with 25 % overall yield. This route pa
sses H-4-3a and H-2-3a which are compared with 3a and its dithione 3b
by IR, UV/Vis, C-13-NMR spectra, redox behavior, and crystal structure
(H-4-3a and 3a). The very low solubility of 3a and 3b prevented furth
er reactions.