Chromium trioxide in acetic acid

Cyclodecanedione has also been prepared by oxidation of sebacoin with chromium trioxide in acetic acid, - Cupric acetate in acetic acid has been used for oxidation of an a-hydroxyketone by Ruggli and Zeller. ... 

Steroidal 17-cyanohydrins are relatively stable towards chromium trioxide in acetic acid (thus permitting oxidation of a 3-hydroxyl group ) and towards ethyl orthoformate in ethanolic hydrogen chloride (thus permitting enol ether formation of a 3-keto-A system ). Sodium and K-propanol reduction produces the 17j -hydroxy steroid, presumably by formation of the 17-ketone prior to reduction. ... 

Oxidation of 17j5-acetoxy-5a-androstan-3-one (1) by chromium trioxide in acetic acid at 55-65° gives the 2,3-seco acid (2). Conversion of the seco acid to its anhydride followed by pyrolysis and distillation gives the A-nor-2-ketone (3) in 45% overall yield. Analogous reactions have been carried... 

Tertiary Af-alkyl-Al,(V-bis(2-fluoro-2,2-dinitroethyl)atnines containing 77-methylene or A -methyl groups are oxidized by chromium trioxide in acetic acid to Af,Al-bis(2-fluoro-2,2-dimtroethyl)formamides [ 5] (equation 82)... 

Oxidation with chromium trioxide in acetic acid cleaved the indole ring to produce intermediate 23 which cyclodehydrated to give prazepam (24). 

Benzo[g]quinolines, e.g. (40), and benzo[g]isoquinolines are oxidized to the corresponding azaanthraquinones using, for example, chromium trioxide in acetic acid (Scheme 28) (79KGS517). 

This oxidation has been used to determine the anomeric nature of sugar residues in oligosaccharides.153 The oligosaccharide is reduced to the alditol, this is acetylated, and the ester is treated with chromium trioxide in acetic acid in the presence of an internal standard. From the sugar analysis of the product, the residues that have survived (and, consequendy, are a-D-linked) may be identified. The... 

Oxidation with chromium trioxide in acetic acid,33 chromium trioxide in acetic anhydride-acetic acid,31 3-chloroperbenzoic acid in methylene chloride65 or benzene,74 or peracetic acid in acetic acid74 gave rise to isatoic anhydrides (64). 

The oxidation of chroman-4-ols to chroman-4-ones, on the other hand, is more easily accomplished, using chromium trioxide in acetic acid (66JCS(C)2013). The same oxidant in pyridine converts chroman-3,4-diols to the 3-hydroxychroman-4-one (65CB1498). 

S. J. Angyal and K. James, Oxidation of carbohydrates with chromium trioxide in acetic acid. I. Glycosides, Aust. J. Chem., 23 (1970) 1209-1221 Oxidation of carbohydrates with... 

I. Hoffman, B. Lindberg, and S. Svensson, Determination of the anomeric configuration of sugar residues in acetylated oligo- and poly-saccharides by oxidation with chromium trioxide in acetic acid, Acta Chem. Scand., 26 (1972) 661-666. 

In order to obtain the trans-fused octalin, the cis-fused octaline 423 was oxidized with chromium trioxide in acetic acid to yield the ketone 424. The latter was treated with bromine in acetic acid to produce the a-bromoketone 425 in a yield of 98%. Dehydrobromination of 425 with. /V-phenylbenz-amidine afforded the a/i-unsaturated ketone 426 in 90-95% yield. The... 

The relative reactivity of primary and secondary positions adjacent to oxygen can be strongly dependent on the nature of the oxidant. For example, treatment of the methyl ethers (8) and (10) with chromium trioxide in acetic acid leads to the formation of the formates (9) and (11), respectively (equations 13 and 14). In direct contrast, n-decyl methyl ether is oxidized exclusively to methyl n-decanoate (83% yield) by ruthenium tetroxide (equation 11). Under similar reaction conations, 3 -cholestanol methyl ether gives cholestan-3-one as the mqjor product, togedier with traces of the corresponding formate. Therefore, at least in the case of ruthenium tetroxide, primary positions appear to be more reactive than tertiary. 

When l-(buten-3-yl)cyclohexanol and l-(penten-4-yl)cyclohexanol are treated with chromium trioxide in acetic acid and acetic anhydride, oxidation at the double bonds results in the formation of carbi xylic acids, which cyclize to form 7- and 8-lactones, respectively [5(55], The same reaction occurs with the cycloheptanol analogues in better yields (equation 282) [56S]. 

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