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Die Darstellung aliphatischer und aromatischer Thio-und Selenoketone sowie einiger ihrer D-, 13C-und 77Se-angereicherten Derivate wird beschrieben. -Bei der elektrochemischen Einelektronen-Reduktion liefern die meisten Vertreter persistente Radikalanionen, die ESR-spektroskopisch untersucht werden. Die gemessenen isotropen '3C-Kopplungskonstanten erlauben den Schlun, daR in der Thio-bzw. Selenoketyl-Gruppe die Spinpopulation am zentralen C-Atom am gronten ist. -Die beobachtete Temperaturabhangigkeit der Kopplungskonstanten ist mit einer planaren Geometrie des Thioketyl-Molekuls in Einklang. Thioketyls, 5 l ) Isotropic ESR Parameters in Thio-and SelenoketylsThe preparation of aliphatic and aromatic thio-and selenoketones and of some of their D-, l3C-, and 77Se derivatives is described. Most of these compounds yield persistent radical anions on oneelectron electroreduction, which are studied by ESR spectroscopy. -The 13C coupling constants allow the conclusion that in thio-and selenoketyls the spin density is mainly located at the central carbon atom. -The observed temperature dependence of the coupling constants is in agreement with a planar geometry of the thioketyl molecule.

A new two step procedure for the synthesis of methyl 2,3-anhydro-a-D-lyxofuranoside and methyl 2,3-anhydro-b-D-ribofuranoside from D-xylose involving the intramolecular Mitsunobu reaction is presented. Likewise, methyl 2,3-anhydro-a-L-lyxofuranoside is obtained from L-arabinose. Cyclic sulfites with D-ribo configuration, synthetic equivalents of the corresponding anhydrosugars, are prepared in three steps from D-ribose.

The answer to the question posed in the title is no; thus, previous claims in the literature have to be corrected. Work in this field has led to the new class of O‐alkyl α‐oxothiocarboxylates.