Ueber die Constitution der selenigen Säure

Toward Carbohydrate Derivatives with a Markedly Acidic Centre: Structures and Reactions of Selenium(IV) Diolates

“…Despite the oxidising power of selenium dioxide, the preparation method proved to be more general than might have been expected. Even with carbohydrate derivatives (13)(14)(15)(16) no oxidation of the substrate was observed. …”

“…Figure 1 shows a 13 C NMR spectrum of a solution (1 ) of equimolar amounts of selenium dioxide and 1,4-anhydroerythritol in methanol. To prevent competition of alkylenedioxy and methyl ester formation, the selenites described in this work were prepared by condensation reactions between selenium dioxide and the corresponding diol or polyol in aprotic solvents (cyclohexane, dioxane).…”

“…The kinetic inertness of the diol esters on the NMR timescale can be demonstrated by using the related propane-1,2-diol as a racemic mixture. The 77 Se NMR spectrum showed two signals and the 13 C NMR spectrum showed two signal sets of different intensities. This observation is consistent with the presence of syn/anti isomerism with respect to the orientation of the substituent at the diol moiety and the oxy substituent of the selenium atom in the colourless oily mixture of (rac-PrpdH -2 )SeO (2).…”

“…Hence SeO 2 and a racemic mixture of trans-cyclohexane-1,2-diol (trans-Chxd) yielded rac-(trans-1,2-ChxdH -2 )SeO (5) as an enantiomeric pair. Due to the lack of syn/anti isomerism and the isochronicity of the enantiomers' signals, the 77 Se NMR spectrum shows one signal and the 13 C NMR spectrum shows one signal set consisting of six lines only. For both cyclohexane-derived diols, crystallisation has not yet succeeded.…”

“…[13] Later, the preparation of dialkyl selenites and some cyclic selenites of diols by the reaction of selenium dioxide with alcohols in aprotic solvents (benzene, dioxane, cyclohexane) was reported. [14][15][16][17][18][19][20][21] Studies concerning alkyl selenites in protic media were performed by Simon and Paetzold who showed that dimethyl selenite (MeO) 2 SeO is quantitatively formed upon dissolution of selenium dioxide in methanol at room temperature.…”