New method of synthesis of β,β′-spiropyrrolidinooxindoles

Russian Journal of Organic Chemistry -     

Synthesis of New N-Sulfonyl Monocyclic β-Lactams and the Investigation of Their Antibacterial Activities

New monocyclic β-lactams 4–6 were synthesized by a ketene-imine [2+2] cycloaddition reaction. The prepared monocyclic β-lactams 4–6 were cleaved by ceric ammonium nitrate (CAN) to give NH-β-lactams 7–9. The NH-β-lactams were converted to N-sulfonyl β-lactams 10–21 by treatment with four different sulfonyl chlorides in the presence of Et₃N and 4-N,N-dimethylaminopyridine (DMAP). Some of these monocyclic β-lactams were active against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis of 2-oxazolones and α-aminoketones via palladium-catalyzed reaction of β,β-dibromoenamides

β,β-Dibromoenamides show two different interesting reactivities based on the choice of R group under the reaction conditions. On the basis of mechanistic studies, both reactions proceed via an intermolecular Suzuki-Miyaura C-C coupling and an intramolecular C-O coupling.     

Synthesis of β,β‘-Difluorinated and β,β’-F-Dialkylated Acetals

Using the phase transfer catalysis technique, a series of fluorinated acetals has been prepared, in basic medium, by action of dicholromethane on 2-mononfluorinated alcohols or 1-F-alkyl 2-fluoroethanols. The identification of these new acetals has been achived by the study cf their ¹H, 19F NMR and their mass spectra.     

Synthesis of Snake-cage Resins and Study of Their Separation Ability

IntroductionSnake-cageresin,alsoca1ledsnake-cagepolyelectrolyte['],isaspecialkindofamphotericresin.ItwasfirstinvestigatedbyHatchM.J.etal.in1957[z].Thetypicalandusefulsnake-cageresinisRetardation11A-8(l1A-8inthecon-text)manufacturedbyDowChemicalCoI,TD.Itissynthesizedbypolymerizingacrylicacidinsidethenetworkofastrongbasicanionexchangeresinwith8%crosslinking.Thus,theresinconsistsofacrosslinkedpolymermatrix,cage,andalinearpolymer,socalledsnake,whichisphysicallytrappedinsidethecage.Thecagepol…     

New Synthesis of β-Anilinochalcones by Regioselective Oxidation of β-Anilinodihydrochalcones Using Iodine–DMSO

β-Anilinodihydrochalcones readily undergo oxidation α to the carbonyl group region in the presence of a catalytic amount of iodine in dimethyl sulfoxide at 130 °C in good yield. Oxidation of allyloxy-substituted β-anilinodihydrochalcones to β-anilinochalcones is a preferred reaction over deallylation.     

A New Synthesis of β-Phenylethyl Alcohols and Phenyl-Acetic Acids via Hydroboration of Phenylketene Dihalides

The synthesis of phenylethyl alcohols and phenyl-acetic acids have been carried out by various methods. We now report a simple synthesis for these compounds via the unprecedented hydroboration-oxidation reaction on phenylketene dihalides.     

The Synthesis of New Spiro β-Lactam and Thiazolidinone Compounds Incorporating Quinones and Their Biological Activity

A series of some fused and spiro heterocyclic compounds such as pyrazolines, isoxazolines, pyrimidines, β-lactams, and thiazolidinone derivatives incorporating compounds 3, 6a–d, 7a–d, 9a–c, 10a–c, 11a–c, 12a–c, and 13a–c have been synthesized by a cycloaddition and cyclocondensation reaction of monochloroacetyl chloride, mercaptoacetic acid, hydrazines, hydroxylamine, urea, and thiourea with the prepared 5a–d and 8a–c.     

Synthesis of β-Fluoroalkyl-β,β-dimethoxy Ketones and β-Fluoroalkyl-β-methoxy-α,β-enones

α-Bromo-β-fluoroalkyl-α,β-enones react with sodium methoxide in methanol to give the corresponding β-fluoroalkyl-β,β-dimethoxy ketones which eliminate methanol molecule to produce a mixture of E/Z-isomeric β-fluoroalkyl-β-methoxyvinyl ketones, the Z isomer prevailing.     

Synthesis and reactivity of alkenyl- and alkynyl-substituted β,β-dihalo-and β,β,β-trichloroamines

β,β-Dihalo- and β,β,β-trichloroamines, obtained by Lewis acid-promoted Petasis-type reaction of α,α-dichlorinated and α,α,α-trichlorinated imines or reduction of α,α-dihaloaldimines, were subjected to a reactivity study and turned out to be remarkably stable compounds. In general, only the bases KO^tBu and NaOMe cause a 1,2-dehydrochlorination with formation of unsaturated α-chloroimines or unsaturated α,α-dichloroimines. Hydrolysis of the α-chloroimines with aqueous oxalic acid resulted in the formation of the corresponding unsaturated α-chloroketones. The reaction of simple β,β-dihaloamines with NaOMe and KO^tBu generated 2-haloprop-2-enylmines and 2,2-dimethoxypropylamines.     

A New,Specific Synthesis of β-Cyclocitral

A new specific synthesis of ρ-cyclocitral is presented. The key step is the dehydration of the trans 2.2.6-trimethylcyclohexanone cyanohydrin by thionyl chloride.     

Synthesis of Curcumone and ar-Turmerone via β-Oxoalkylation Process

Abstract

In 1974 I outlined a synthesis of ar-turmerone (1)¹ by controlled chain extension from the acetyl terminus of mesityl oxide, using the Diels-Alder cycloaddition and its retro version to protect and reclaim, respectively, the unsaturated moiety. Recently, a simpler approach to ar-turmerone and curcumone (2) has been brought to completion and is described in the following.     

Synthesis of β-D-xylofuranosyl- and 2,2′-anhydro-1-β-D-lyxofuranosylpyrimidine nucleosides

-D-Xylofuranosylpyrimidines were obtained by condensation of silyl derivatives of pyrimidines with 1,2-di-O-acetyl-3,5-di-O-benzoyl-D-xylofuranose with subsequent deprotection of the sugar fragment. Refluxing 2-O-tosyl derivatives of nucleosides with NaI results in the formation of 2,2-anhydro-compounds.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1137–1141, June, 1993.     

Effect of Rotation Rate on the Formation of Platinum-modified Polyaniline Film and Electrocatalytic Oxidation of Methanol

The oxidation of methanol was investigated on platinum-modified polyaniline electrode.Changes in the electrode rotation rates (Ω) during platinum electrodeposition remarkably affect the formation and distribution of platinum in the polymer matrix and consequently lead to different currents of methanol oxidation. The results show that platinum loading is proportional to rotation rates Ω^1/2.     

Synthesis of β-carbolines via a silver-mediated oxidation of tetrahydro-β-carbolines

The oxidation of tetrahydro-β-carbolines to β-carbolines using silver carbonate was developed as an alternative to current methods. The oxidation is extremely mild and provides the products in modest to good yields after purification. A number of functional groups are tolerated by this methodology, including reduction-sensitive groups which are often cleaved with other methods. Though the mechanism is not fully understood, the reaction proceeds in an open flask, is not sensitive to light or moisture, and provides a viable synthetic route to compounds that are not easily prepared via other methodologies.     

Synthesis of α,β- and β-Unsaturated Acids and Hydroxy Acids by Tandem Oxidation,Epoxidation, and Hydrolysis/Hydrogenation of Bioethanol Derivatives

We report a reaction platform for the synthesis of three different high-value specialty chemical building blocks starting from bio-ethanol, which might have an important impact in the implementation of biorefineries. First, oxidative dehydrogenation of ethanol to acetaldehyde generates an aldehyde-containing stream active for the production of C₄ aldehydes via base-catalyzed aldol-condensation. Then, the resulting C₄ adduct is selectively converted into crotonic acid via catalytic aerobic oxidation (62 % yield). Using a sequential epoxidation and hydrogenation of crotonic acid leads to 29 % yield of β-hydroxy acid (3-hydroxybutanoic acid). By controlling the pH of the reaction media, it is possible to hydrolyze the oxirane moiety leading to 21 % yield of α,β-dihydroxy acid (2,3-dihydroxybutanoic acid). Crotonic acid, 3-hydroxybutanoic acid, and 2,3-dihydroxybutanoic acid are archetypal specialty chemicals used in the synthesis of polyvinyl-co-unsaturated acids resins, pharmaceutics, and bio-degradable/ -compatible polymers, respectively.     

Synthesis of β-carbolines from aldehydes and ketones via the α-siloxy α,β-unsaturated esters

We report an efficient method for the synthesis of β-carbolines from α-siloxy α,β-unsaturated esters, which are accessible from a variety of aldehydes and ketones.     

Synthesis of a New β-Mercaptoalcohol

Mercaptoalcohols are a rare class of natural products. Some optically active mercaptoalcohols have been used as catalysts in asymmetric reduction of prochiral Ketone1,2. In this letter, we report the synthesis of a new optically active (-mercaptoalcohols, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol 7, from L- valine.Our first attempt is showed in Scheme 1. According to literature's method L-valine was converted to (S)-2-Hydroxy-3-methylbutanoic acid 21,2. 2 was treated with MeOH/SOCl2…     

Synthesis and Stereostructure of New β-Lactam Derivatives of1,5-Benzothiazepines

Becauseoftheimportanceofbenzothiazepinederivatives,whichexhibitversatilebiologicalactivities.thechemistryofbenzothiazepinehasarousedinterestforalongtime'-'.Inourpreviouspapers.wehavereportedthesynthesisandelucidationofthestereostructureoftwokindsofl,5-benzothiazepine-6-lactams'-'.InordertoelucidatetheinfluenceofthesizeofthesubstituentatC-2ontheconfigurationof0-lactammoietyandfurtherstudythestereochemistryofthecycloadditionreaction.wepreparedaseriesofnewfi-lactamderivativesofI.5-benzothiazepine…     

Synthesis and Complexation Study of New Aminoalkynyl−amidinate Ligands

The current library of amidinate ligands has been extended by the synthesis of two novel dimethylamino-substituted alkynylamidinate anions of the composition [Me₂N−CH₂−C≡C−C(NR)₂]⁻ (R = ⁱPr, cyclohexyl (Cy)). The unsolvated lithium derivatives Li[Me₂N−CH₂−C≡C−C(NR)₂] ( 1 : R = ⁱPr, 2 : R = Cy) were obtained in good yields by treatment of in situ-prepared Me₂N−CH₂−C≡C−Li with the respective carbodiimides, R−N=C=N−R. Recrystallization of 1 and 2 from THF afforded the crystalline THF adducts Li[Me₂N−CH₂−C≡C−C(NR)₂] ⋅ nTHF ( 1 a : R = ⁱPr, n=1; 2 a : R = Cy, n=1.5). Precursor 2 was subsequently used to study initial complexation reactions with selected di- and trivalent transition metals. The dark red homoleptic vanadium(III) tris(alkynylamidinate) complex V[Me₂N−CH₂−C≡C−C(NCy)₂]₃ ( 3 ) was prepared by reaction of VCl₃(THF)₃ with 3 equiv. of 2 (75 % yield). A salt-metathesis reaction of 2 with anhydrous FeCl₂ in a molar ratio of 2 : 1 afforded the dinuclear homoleptic iron(II) alkynylamidinate complex Fe₂[Me₂N−CH₂−C≡C−C(NCy)₂]₄ ( 4 ) in 69 % isolated yield. Similarly, treatment of Mo₂(OAc)₄ with 3 or 4 equiv. of 2 provided the dinuclear, heteroleptic molybdenum(II) amidinate complex Mo₂(OAc)[Me₂N−CH₂−C≡C−C(NCy)₂]₃ ( 5 ; yellow crystals, 50 % isolated yield). The cyclohexyl-substituted title compounds 2 a , 4 , and 5 were structurally characterized through single-crystal X-ray diffraction studies.