Triphenylphosphine ozonization

Ozonolysis. Ozonolysis of the methylhexadiene polymer was conducted (21)at room temperature on a solution of 1,03 g. polymer in 20 ml. tetrahydrofuran with the aid of the Wellsbach ozonizer. The end point for the ozonolysis was observed after about 15 min. by the reaction of excess ozone with starch-iodide solution. Triphenylphosphine was added to the reaction mixture and allowed to react at room temperature for 60 hr. The resulting product was analyzed by GLC (Hewlett Packard 5750, Porapak Q 10 ft. x 1/8 in. column at 110°C, helium pressure 60 psi, thermal conductivity detector at 190°C, injector 200°c). 

Hydrolysis of bromodifluoromethyl tnphenylphosphonium bromide, yielding bromodifluoromethane and triphenylphosphine oxide, proceeds via difluorocar-bene rather than by the bromodifluoromethyl carbanion [46 (equation 46). Bromodifluoromethane is a candidate for the replacement of Halon 1301 (CFjBr), a fire extinguishant presumed to cause damage to the stratospheric ozone layer... 

Under somewhat milder conditions (200°C), the reaction does not proceed as far as removing the functional groups, and the result is merely the hydrogenation of multiple bonds [38,39]. This is an efficient means of structure elucidation, especially when combined with ozonolysis [40,41 ] to establish the locations of multiple bonds in the molecule. In ozonolysis the substance supposed to contain a double bond is dissolved in CS2, ozonized at about —70°C and the ozonide is reduced with triphenylphosphine to produce aldehydes and/or ketones characteristic of the moieties linked by the double bond. 

Potassium permanganate. Dimethyl sulfide-Chlorine. Dimethyl sulfoxide. Dimethyl sulfoxide-Chlorine. Dimethylsulf-oxide Sulfur trioxide. Dipyridine chro-mium(VI) oxide. Iodine. Iodine-Potassium iodide. Iodine tris(trifluoroacetate). Iodosobenzene diacetate. Isoamyl nitrite. Lead tetraacetate. Manganese dioxide. Mercuric acetate. Mercuric oxide. Osmium tetroxide—Potassium chlorate. Ozone. Periodic acid. Pertrifluoroacetic acid. Potassium ferrate. Potassium ferricyanide. Potassium nitrosodisulfonate. Ruthenium tetroxide. Selenium dioxide. Silver carbonate. Silver carbonate-Celite. Silver nitrate. Silver oxide. Silver(II) oxide. Sodium hypochlorite. Sulfur trioxide. Thalli-um(III) nitrate. Thallium sulfate. Thalli-um(III) trifluoroacetate. Triphenyl phosphite ozonide. Triphenylphosphine dibromide. Trityl fluoroborate. 

Solvent effects on the oxidation of triphenylphosphine by perbenzoic acid have been reported. The second-order rate constants are directly proportional to the dielectric constant of the solvent. Oxidation of methylphenyl-propylphosphine with 3-chloroperbenzoic acid or ozone proceeds with retention of configuration. The reaction of alkyl- or aryl-phosphines with dialkyl peroxides or polyperoxides in aqueous solvents leads to the formation of alcohols or glycols, respectively. ... 

Ozonides are decomposed thermally [242, 243] or by triphenylphosphine powder [238—241, 244]. For thermal decomposition a micro-reactor is applied [245] in which a sample of volume up to 5jul can be ozonized, decomposed and injected into a gas chromatograph without losses of the compound. 

The synthesis of 3 may be simplified further by linking the C20- units 59 or 60 oxidatively or reductively, respectively. Thus reduction of 60 with low-valency titanium compounds [64] or oxidation of 59 with triphenylphosphite-ozone adduct [65] afford 3 in yields of 85% and 75%, respectively. In a process developed at BASF the phosphonium salt 59 is reacted with hydrogen peroxide in aqueous alkaline solution [62]. After separation of triphenylphosphine oxide and thermal isomerization, (all- )-3 conforming to type specifications is obtained in yields of approximately 70% based on vitamin A acetate (26) (Scheme 17). 

Phosphines and phosphites are readily oxidized by ozone (81). The 1 1 adducts have pentacovalent phosphorus structures (82). Ozonides are reductively cleaved by triphenylphosphine (83). 

Phosphines react with many compounds to remove oxygen and form phosphine oxides which contain the strong phosphoryl P=0 bond. Thus, triphenylphosphine forms triphenylphosphine oxide with ozone, nitric oxide, dinitrogen tetroxide or nitrosyl chloride. 

A mixture of phenanthrenequinone, the equivalent amount of trimethyl phosphite, and methylene chloride kept 0.5 hr. at room temp, under Ng, cooled to —70°, and treated with O3 from a Welsbach T-23 ozonator until the reddish-brown color is discharged diphenoyl peroxide (Y 50%) allowed to react with triphenylphosphine (or trimethyl phosphite) diphenic anhydride (Y over 80%). Also benzoyl peroxide brom benzil s. F. Raminez, N. B. Desai, and R. B.Mitra, Am. Soc. 83, 492 (1961). 

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