Selenous acid ester esters

Peroxyseleninic acids Selenonic acids Selenous acid esters Selenious acid esters 15... 

Selenous acid ester halides from selenous acid esters... 

Oxidative rearrangement of 5a-cholestan-3-one (62) with hydrogen peroxide and a catalytic amount of selenic acid affords 2a-carboxy-A-nor-5a-cholestane, isolated in about 35 % yield as the methyl ester (63)." However, the reaction gives a complex mixture of A-nor- and seco-acids, and under... 

Formate esters behave as typical carbonyl compounds in reactions with a number of ylides, eliminating phosphine oxide and forming vinyl ethers, e.g. (33).35 Stabilized phosphoranes are able to condense with the carbonyl group of cyclic thioanhydrides (34).38 Quinoline derivatives, e.g. (35), are obtained from the condensation of dicar-boalkoxy-ylides with isocyanates.37 Benzoyl isothiocyanates and keto-phosphoranes give quantitative yields of (36), which are unreactive in Wittig reactions but can be readily oxidized by selenous acid.38 The products obtained from reactions (Scheme 9) with the triazolinedione (37) depend upon the stability of the ylide used.39... 

Selenium-oxygen bonds. The Se chemical shifts of some inorganic selenium-oxygen compounds are listed in the Tables 2 and 3. It is apparent that Se (Vl)-species are much more shielded (5 = 944-1076 Table 2) than the Se (IV)-species (5 = 1263-1559 Table 3). This holds as well for SeO3, the anhydride of selenic acid (H2SeO4), the halogen derivatives and its alkyl esters and amides. 

SELENIC ANHYDRIDE (13768-86-0) OgSe Noncombustible solid. Violent reaction with water, forming selenic acid. A strong oxidizer. Violent reaction with many substances including reducing agents, hydrides, nitrides, and sulfides cyanides, esters, combustible materials, active metals, organic substances, aldehydes, alkenes, carboxylic acids, isocyanates, and thiocyanates. Attacks most metals in the presence of moisture. 

Chloroseleninic acid esters Selenous acid ester halides... 

Similarities are noted between the mass spectra of aliphatic and aromatic selenides with analogous sulphides and phosphines. " Selenoxides show the expected fragments derived from the selenate rearrangement product " " Extensions of these studies cover selenium dihalides (no moleculm ion is seen " ), seleninic acids and esters, " and selenones. Mass spectra of diaryl tellurides are very much like those of S and Se analogues. ... 

Another mechanism has been proposed for this reaction. In this case, it is suggested that a 0-ketoseleninic acid, -C(=0)CHSe(=0)0H is involved as the intermediate, rather than the selenate ester. This just highlights the fact that very few proposed mechanisms are actually proved in reality. Often, all that may be said for any particular mechanistic pathway is that it accounts for all the kinetic... 

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