Tellurocarboxylic acid

Only a few representatives of tellurocarboxylic acid anhydrides have been prepared from tellurium, sodium telluride, or bis[trimethylsilyl] tellurium and alkanoyl or arenoyl chlorides. Diacyl telluriums are stable at 20°, however, they are very sensitive to air and moisture. 

Te-Esters of tellurocarboxylic acids were prepared from tellurolates and carboxylic acid chlorides or anhydrides, and from sodium telluride and aroyl chlorides". The following types of 7e-organo tellurocarboxylates have thus far been synthesized ... 

Scheme 6). Similarly, for seleno- and tellurocarboxylic acids, selenol and se-lenoxo, and tellurol and telluroxo forms may co-exist, respectively. Previous studies concerning the tautomerism of thiocarboxylic acids indicate that the thiol form (I) with the s-cis (syn) conformation is the predominant species. 

Tellurocarboxylic acid esters from carboxylic acid chlorides COCl - COTeR and ditellurides cf. 36, 603 via Na-tellurocarboxylates, alkyl tellurocarboxylates, s. T. Kanda et al.. Tetrahedron Letters 30, 1829-32 (1989). 

A large number of stable /e-organo tellurocarboxylates were prepared from tellurolates and aliphatic1,2 or aromatic2 carboxylic acid chlorides or aliphatic carboxylic acid anhydrides . The tellurolates were obtained by reduction of diorgano ditelluriums with sodium borohydride. 

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