Fieser reagent oxidant

Two independent syntheses of quadrone eiiq>loyed an allylic oxidation with rearrangement, as shown in equation (3), where the chromium trioxide-(3,5-dimethylpyrazole) reagent (CrOs DMP) was used. In some cases, the success of the reaction strongly depends on the nature of the oxidant, as shown in an iq>proach to (-)-upial (equation 4). Here the chi ium trioxide-heterocycle reagents, which are weaker oxidants, are quite inferior compared to the Fieser reagent ... 

Chromium trioxide [chromium(VI) oxide, chromic add, or chromic anhydride], Cr03 (dark red crystals, mp 195 °C), is one of the most powerful and universal oxidants. It is applied in solutions in acetic acid, dilute sulfuric acid, a mixture of acetic acid and dilute sulfuric acid, dilute sulfuric acid and acetone (Jones reagent), acetic anhydride and acetic acid (Fieser reagent) [535], water, water and ether [536,537,535], dichloromethane [539],... 

Not only allylic alcohols but also homoallylic alcohols can be epoxi-dized. A peculiar transannular oxidation takes place when 1-methyl-4-cycloocten-l-ol is treated with the Fieser reagent, [CrOj-(CH3C0>20-CH3C00H], or with pyridinium chlorochromate. Two dia-stereomeric keto oxides are formed in different ratios (equation 281) [535],... 

Favorski rearrangement, 1092, 1202 Fehling solution, 390 Fenton s reagent, see Hydrogen peroxide, with salt or oxide catalysts Ferric chloride, 297, 390-392, 702, 814 anhydrous, 392 Ferrocene, 181, 392 Ferrous chloride, 392 Ferrous sulfate, 393 Fieser reagent, 145 Fieser s solution, 222, 393, 737 Filter aid, see Celite Fischer indole synthesis, 899 Fischer reagent, see Karl Fischer reagent Fisetin, 64... 

Anhydrous CrO -acetic acid (Fieser reagent ). The oxidation is done by stirring a solution of the alcohol in anhydrous acetic acid with suspended chromic anhydride at a controlled temperature. The oxidant is insoluble in the anhydrous solvent but dissolves as oxidation progresses addition of water precipitates the product. The reagent oxidizes the side chain of 2-acetoxy-3-alkyl-1,4-naphthoquinones, for example ... 

Tetrabutylammonium chlorochromate [54712-57-1] M 311.9, m 184-185 . It recrystaUises from EtOAc/hexane. IR 920cm in CHCI3 [SantanieUo Synthesis 749 1983, Fieser Fieser Reagents for Org Synth 12 458]. Powerful oxidant and possible carcinogen. 

N-Methylmorpholine Oxide-Hydrogen Peroxide Oxidation. The preparation of A-methylmorpholine oxide-hydrogen peroxide is described in Reagents for Organic Synthesis by L. Fieser and M. Fieser. 

Earlier synthetic applications of selenium dioxide for the introduction of the carbonyl functionality at activated positions, to dehydrogenation of highly activated saturated sites, to hydroxylation of activated carbon-bearing positions, particularly at allylic(propargylic) sites, and to oxidative bond cleavage are presented in a few books devoted to selenium chemistry [2] or oxidation reactions [14]. These procedures are also permanently included in the Fieser Fieser compendium of reagents [15]. 

Various forms of H2Cr04 and of Cr03 are used for this reaction. For a review, see Cainelli, G. Cardillo, G. Chromium Oxidations in Organic Chemistry, Open Court Publishers Co., La Salle, IL, 1981, pp. 118-216. For discussions, see Fieser, L.F. Fieser, M. Reagents for Organic Synthesis, Vol. 1, Wiley, NY, 1967, pp. 142-147, 1059-1064, and subsequent volumes in this series. 

USE In the manuf of other selenium compounds as a reagent for alkaloids as oxidizing agent L. F. Fieser, M. 

Silver carbonate supported on Celite (Fetizon s reagent) has found wide application in organic chemistry (Fieser and Fieser, 1977). It has been used mainly for the oxidation of alcohols and lactones for the oxidative... 

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