Raju Penmasta

Direct α-hydroxylation of ketones under acidic conditions using [bis (trifluoroacetoxy)] iodobenzene

[Bis(trifluoroacetoxy)] iodobenzene and trifluoroacetic acid in CH3CN/H2O reacts with aromatic, heteroaromatic, and aliphatic ketones to afford α-hydroxyketones in moderate to good yields.

Inversion of configuration of α-trisubstituted (neopentyl) type secondary alcohols

Abstract A variety of hindered α-trisubstituted optically active secondary alcohols has been converted into their enantiomers by treating the corresponding triflates with KNO 2 in DMF in the presence of 18-crown-6 at room temperature.

Hypervalent iodine oxidation of trimethylsilyl enol ethers of ketones: a direct synthesis of α-keto triflates

Abstract α-Trifluoromethanesulfonoxy ketones (α-keto triflates) have been synthesized under very mild conditions by the reaction of silyl enol ethers of ketones and trimethylsily trifluormethanesulfonate/iodosobenzene in dichloromethane.

Possible role of Lewis acid catalysis in the oxidation of alkenes and α,β-unsaturated ketones using bleomycin-Zn(II) and bleomycin-Fe(III)-iodosylbenzene in aqueous methanol

Abstract C6H5IO in CH3OH-H20 is activated towards electrophilic attack upon various alkenes by Fe(ClO4).9H2O, FE(III) bleomycin and ZN(II) bleomycin. The results imply that direct transfer of oxygen from an Fe(V)=0 intermediate is not required in the mechanism of oxygenation by iron-containing species, and that much earlier work is questionable as models for biological oxygenation.

Synthesis of 1,4-diketones by the coupling reaction of trimethylsilyl enol ethers with lead tetraacetate

Abstract Synthesis of 1,4-diketones in good yields was achieved by the coupling reaction of the trimethylsilyl enol ethers of acetophenone, thiophene or furan with lead tetraacetate in dry dichloromethane and tetrahydrofuran at −78°C.

Novel pentafluorophenyl hypervalent iodine reagents

Abstract The novel C 6 F 5 I(OH)OTs has been synthesized and shown to undergo ligand exchange with C 6 H 5 I, iodonium ylide formation with dimedone and iodonium salt formation with anisole.

Mild carbon–carbon bond cleavage of carbonyl compounds using pentafluoroiodobenzene bis(trifluoroacetate)

Acetophenones, α-hydroxyacetophenones, deoxybenzoin, benzoin, and benzil are cleaved oxidatively with pentafluoroiodobenzene bis-(trifluoroacetate) in wet benzene at room temperature to give the corresponding benzoic acids; cyclohexanone and dimedone are cleaved to give the diacids adipic acid and 3,3-dimethylglutaric acid, respectively.

A Comvewiemt Synthesis of 1-Aminopolycycloalkames and Their Tosylate Salts

Abstract Syntheses of oridgehead 4-amino-l-bromopentacy-clo[4.3.0.02.5 O3,8.O4,7]nonan-9-one ethyl ene acetal (6), 4-iodocubyl-l-ammonium tosylate (8) and 1-adamantane ammonium tosylate (10) are described.

A convenient synthesis of 1α,25-dihydroxy-28-norvitamin D2

Abstract The title compound was synthesized via the Julia olefination using ring B-diene protected 3β-hydroxy-23,24-bisnorchola-5,7-diene-22-al acetate and the side-chain synthon 2-methyl-4-phenylsulfonyl-2-(tetrahydropyranyloxy)butane. Ring B-deprotection, photolysis, Paaren-DeLuca hydroxylation and separation of the 5,6 E and Z stereoisomers completed the synthesis in overall 3% yield.

Functionalized cubanes. Oxidative displacement upon methyl 4-iodocubane carboxylate using hypervalent iodine reagents

Abstract Methyl 4-iodocubane carboxylate undergoes substitution via ligand exchange with the hypervalent reagents C6H5I(OH)OTs, C6H5I(OH)OMs and C6H5ICl2.