The optically pure five-membered ring thionocarbonates (la-3a), carbonates (lb-3b), sulfites (cis-and transió, 2c, 3c), phosphite (2d), and 2-bromoand 2-chloromethyl-1,3-dioxolanes (cis-and irons-le, 2e, 2f) were prepared from the three title diols by standard methods and their uv and CD spectra were measured in various solvents over the range 185-400 mg at room temperature. The CD spectra of la-3a display two well-defined Cotton effects of opposite signs and of diverse intensities centered at 222-235 and 325 mg, related to the uv ir -* * and n -* * transitions, respectively. The sign of the long-wavelength Cotton effect is associated with the chirality of the heterocycle ring. A positive ellipticity for the n -*• ir* transition is assigned to thionocarbonates

Aus den drei Diolen (I), (III) und (V) werden cyclische Thionocarbonate (IIa) (IVa) und (VIa), Carbonate (b‐Reihe), Sulfite (c‐Reihe) und Phosphite (d‐Reihe) hergestellt.