Silver acetate iodine, oxidations with

The preparation of Pans-1,2-cyclohexanediol by oxidation of cyclohexene with peroxyformic acid and subsequent hydrolysis of the diol monoformate has been described, and other methods for the preparation of both cis- and trans-l,2-cyclohexanediols were cited. Subsequently the trans diol has been prepared by oxidation of cyclohexene with various peroxy acids, with hydrogen peroxide and selenium dioxide, and with iodine and silver acetate by the Prevost reaction. Alternative methods for preparing the trans isomer are hydroboration of various enol derivatives of cyclohexanone and reduction of Pans-2-cyclohexen-l-ol epoxide with lithium aluminum hydride. cis-1,2-Cyclohexanediol has been prepared by cis hydroxylation of cyclohexene with various reagents or catalysts derived from osmium tetroxide, by solvolysis of Pans-2-halocyclohexanol esters in a manner similar to the Woodward-Prevost reaction, by reduction of cis-2-cyclohexen-l-ol epoxide with lithium aluminum hydride, and by oxymercuration of 2-cyclohexen-l-ol with mercury(II) trifluoro-acetate in the presence of ehloral and subsequent reduction. ... 

Dibenzyl selenium di-iodide, (C6H5.CH2)2SeI2.—When dibenzyl selenide is heated with iodine in chloroform solution, dark violet crystals of the di-iodide separate, M.pt. 97° C. The halogen in this and the foregoing compound is removed by alkali, silver oxide or silver acetate. 

Dihalofuroxans are formed on dehydrohalogenation of dihaloximes and when halogens react with mercury or silver fulminates. Iodine with the silver salt of phenylnitrosolic acid gives diphenylfuroxan. Boron trifluoride in acetic anhydride reacts with 2-(ethoxycarbonyl-nitromethylene)thiazolidine to give diethoxycarbonyl furoxan. In each case nitrile oxides are likely or proven intermediates. 

Further studies on the photochemistry of friedelin have led to the isolation of the unsaturated aldehyde (130).105 Silver oxide oxidation of (130) gave the known putranjivic acid. Irradiation of friedelin in the presence of acetone afforded the hydroxy-ketone (131).106 Photochemically initiated reaction of 7/3-hydroxyfriedelane and 3/3,7/3-dihydroxyfriedelane with lead tetra-acetate-iodine... 

These olefins were transformed into unsaturated acetates by Woodward s protocol with iodine, silver acetate, and acetic acid. Saponification and subsequent oxidation of the liberated alcohols with Collin s reagent resulted in a 2 1 mixture of conjugated enones, 162 and 163, in mediocre yields (Scheme 16). The minor enone 163 was transformed into the cyanoketone 164 by 1,4-addition using... 

Alkenes can be oxidized to diols by the Prevost method, which involves the reaction of an alkene with iodine and silver acetate. The frans-1,2-diacetate formed first on hydrolysis gives frans- 1,2-diols (Scheme 7.26). In the Woodward variation of the Prevost reaction, the monoester is formed under aqueous conditions, which on hydrolysis gives ds-diol. 

Some BS-analogues with additional double bond in the A-cycle were synthesized using the a-cis-hydroxylation method developed by us earlier (13-16). As shown in Figure 4, the oxidation of 2 with osmium tetroxide followed by bromination and dehydrobromination led to dienoketone 13 which was subjected to hydroxylation under the action of iodine and silver acetate in aqueous acetic acid to give the unsaturated BS analogue 14. 

Fuming nitric acid in the presence of acetic anhydride oxidizes iodine, producing the compound I(OCOCH3)3. On oxidation of iodine with concentrated nitric acid in the presence of acetic anhydride and phosphoric acid, the compound IP04 is obtained. No direct structural information is available for these compounds, but they are probably best regarded as covalent. Nevertheless, electrolytic dissociation can occur and when a saturated solution of I(OCOCH3)3 in acetic anhydride is electrolyzed the quantity of silver iodide formed at a silvered platinum gauze cathode is in... 

C-17, gave 3 -melhanesulphonyloxyandrost-5-en-17 -ol acetate (403). Diborane addition to the A -double bond and oxidation afforded the 6-keto-derivative (404). Elimination of the 3-mesylate, followed by iodine and silver acetate treatment furnished the 2-acetoxy-3-alcohol (405), which was successively acetylated at C-3, brominated at C-7, and dehydrobrominated to the triacetoxy-A -6-ketone (406). Enol acetylation of the conjugated carbonyl furnished the tetra-acetate (407), which was treated with peracid and then hydrolysed and isomerized at C-5 to yield the desired tetraol (408). ... 

Saturated (and some unsaturated) long-chain hydroxy compounds can be converted to tetrahydrofurans by oxidation with reagents that convert the alcohol (ROH) to its alkoxide radical (RO ). These include lead tetra-acetate, silver oxide/bromine, mercuric oxide/iodine, sodium hypochlorite (domestic bleach), and A -iodosuccinimide (Scheme 12). 

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