The Reaction of ∝, β-epoxyketones with methoxymethylenetriphenylphosphorane, A New Approach to ∝-alkylsubstituted-γ-hydroxy-d, β-unsaturated aldehydes

The reaction of α, β-epoxyketones with methoxymethylenetriphenyl-phosphorane provides a method for the preparation of α-alkylsubstitutedγ-hydroxy-α, β-unsaturated aldehydes with one carbon homologation andretention of configuration.     

Reaction of Perfluoroalkanesulfinyl Chlorides with Enamines: A Facile Synthesis of α-Perfluoroalkanesulfinyl Ketones and Aldehydes

The reaction of perfluoroalkanesulfinyl chlorides with enamines was achieved in the presence of triethylamine, and α-perfluoroalkanesulfinyl carbonyl compounds were obtained in moderate to good yields after hydrolysis of the reaction intermediates with dilute hydrochloric acid.     

Unusual Reaction of Diazo Compounds with Enamines

Transition metal catalyzed decomposition of diazo compounds and consequent transformations constitute various synthetic useful reactions in the past decades. The catalytic addition of diazo compounds to olefins generally provides cyclopropanes in high yield. However the reaction of electron-rich enamines with diazo compounds gave variable results. Wenkert et al. reported the reaction of enamines with ethyl diazoacetae (EDA) in the presence of cuprous chloride or silver oxide unexpectedly gave…     

A New Condensation Reaction of β-Keto-δ-valerolactone with Substituted Aniline

Pyronesareimportantintermediatesofpesticidesandpharmaceuticals'.Recentlythebiologicalactivitiesofpyronederivativeshavedrawngreatinterest,butfewliteraturesonthebiologicalactivitiesof0-keto-8-valerolactonederivativeswerereported.The3positionof0-keto-5-valerolactonesisparticularlyreactive,acylationcantakeplaceinthisposition'-'.Herewereportanewcondensationreactionof6-keto-5-valerolactone,bymeansofwhichnewcarbon-carbondoublebondwasformedandaserisofnewanilinomethylenecompoundswereobtained.Synthesiso…     

Reaction of Benzylidene Chlorides with О-Methyl Diethylphosphinothioate

Russian Journal of General Chemistry - О-Methyl diethylphosphinothioate reacts with benzylidene chlorides to form arenecarbthioaldehyde trimers and diethylphosphinoyl chloride. This result...     

The Michael Addition of Enamines to Propenamidines. A Convenient Synthesis of 2β-Amidinoethylcyclo-Alkanones by Amidinoethylation Reaction

A variety of propenamidines 3 have been reacted with enamines of cyclopentanone and cyclohexanone giving after hydrolysis of the Stork enamine 6, 2-β-amidinoethylcyclopentanones 8 and -hexanones 7. This reaction illustrates the electrophilic character of the C=C double bond due to the conjugated amidine function, thus providing with propenamidines 3 a new class of Michael acceptors for enamines.     

Reaction of 1-Iodoalkynes with Tin Metal: A New Approach to the Sn–Csp Bond Formation

Russian Journal of General Chemistry - Tin iodoalkynylides were synthesized by the reaction of 1-iodoalkynes with tin metal. The scope of the reaction and the composition of the resulting mixtures...     

The Reaction of β-Aminoenones with Cyanamide. A High Efficient Synthesis of 2-Aminopyrimidines

β-aminoenones react with cyanamide, molar ratio 1:2, to yield 2-aminopyrimidines in nearly quantitative yields.     

Reactions of β-Ketophosphonates and Enamine Phosphonates with Electrophilic Reagents

Abstract

The direction of the reactions of β-ketophosphonates and enamine phosphonates strongly depends on the structure of substrates and electrophiles. Regio- and stereoselectivity on the reaction of anionic P-ketophosphonates depends on the nature of cation and solvent. The yield of O-products increases substantially when going from alkylation to acylation, and in particular to phosphorylation.     

Semisynthetic β-Rhodomycins: A New Approach to the Synthesis of 4-O-Methyl-β-Rhodomycins

ABSTRACT

Syntheses of 4-O-methyl-β-rhodomycins are described. Glycosylation (trimethylsilyl triflate, dichloromethane-acetone 10:1, -30 °C) of 4-O-methyl-10-O-p-nitrobenzoyl-β-rhodomycinone, obtained from β-rhodomycinone (βRMN) in a 6-step synthesis, with 1-O-tert-butyl(dimethyl)silylated derivatives of 4-O-acetyl- or 4-O-p-nitrobenzoyl-2,3,6-tri-deoxy-3-trifluoroacetylamino-β-L-arabino- and lyxo-hexopyranoses or 2,6-di-O-acetyl-2,6-dideoxy-β-L-lyxo-hexopyranose afforded 7-O-α-L-glycosyl-β-rhodomycinones. Removal of the O- and N-acyl groups with 0.1M and 1M NaOH gave the 7-O-(3-amino-2,3,6-trideoxy-α-L-arabino- and lyxo-hexopyranosyl)-4-O-methyl-β-rhodomycinones and 7-O-(2,6-dideoxy-α-L-lyxo-hexopyranosyl)-4-O-methyl-β-rhodomycinone.     

A New Approach to α—Bromochalcones

α-Bromo benzolymethylene triphenylphosphorane 3 has been synthesized by the reaction of benzoylmethylene triphenylphosphorane 1 with N-bromosuccinimide in the yield of 87% and can react with aromatic aldehydes 4 to give α-bromochalcones 5 in good yields.     

The Reaction of α-Amino-Substituted Diphenylphosphine Oxides with Elemental Sulfur and Selenium. A New Route to Thio- and Selenoamides

Abstract

Lithiated α-amino-substituted diphenylphosphine oxides 1 showed an interesting reactivity towards sulfur and selenium, leading to the formation of thioamides 2 and selenoamides 3, which could be isolated in good yields. Two equivalents of the chalcogene were found to be needed for complete conversion of the phosphine oxide anions. In the case of sulfur, diphenylphosphinothioic acid 4 was isolated as a side product, thus explaining the stoichiometry of the reaction (Scheme 1).     

Reaction of N‐Nonaflyl and N‐Cyano‐Benzotriazoles with Enamines

N‐Nonaflyl‐benzotriazole 1a reacts with enamines 2 in tetrahydrofurane (THF) at room temperature to afford o‐nonafluorobutansulfonamido‐phenylazo‐enamines 3 in 74–81% yield. Compound 1a reacts with 1‐diethylaminobutadien 2f twice, affording pyridazine derivative 3f in 20% yield. Ringopening of N‐cyano‐benzotriazole 1b with pyrrolidinocyclohexene 2a affords, under cleavage of pyrrolidine 1,2,3,4‐tetrahydro‐dibenzo[4,5:e]imidazo[1,2‐b][1,2,4]triazine 4 in 43% yield.     

The Reactions of Phosphoryl - Stabilized Carbanions with α,β-Unsaturated Cycloalkenones Derivatives

Abstract

The effects of the β-leaving group of the cycloalkenone on the regioselectivity of nucleophilic addition by RCHLiP(O)(OEt)₂ are discussed.     

Reaction of β-acyl-β-nitrostyrenes with benzenethiols

β-Acetyl- and β-benzoyl-β-nitrostyrenes reacted with benzenethiols under mild conditions to give previously unknown 4-aryl-4-(arylsulfanyl)-3-nitrobutan-2-ones and 3-aryl-3-(arylsulfanyl)-2-nitro-1-phenylpropan-1-ones, respectively, which were isolated as pure diastereoisomers or mixtures of two diastereoisomers.     

A New Chiral β-Sulfiny Dienophile for Asymmetric Diels-Alder Reaction

Reaction of a chiral cis-β-sulfinylacrylate, prepared from (1R,2S,3R)-3-mercapto-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol, and cyclopentadiene produced Diels-Alder cycloadductswith extremely high diastereoselectivity.     

The Reaction of Molybdenum with 2,3-Dihydroxynaphthalene

[H2N（CH2）3NH312[MoO2（C10H6O2）2] （1） was synthesized by the 2,3-dihydroxynaphthalene in the mixed solvent of CH3OH, CH3CN reaction of （n-Bu4N）4[Mo8O26] with and 1,3-propanediarnine. （C5HllN2）2- [HeN（CH2）3NH2][MoO2（CloH6O2）2] （2） was obtained by the reaction of Na2MoO4.2H20 with 2,3-dihydroxynaphthalene in the same solvent above. Both of the complexes possess complex anion [Mo（VI）O2（OC10H6O）2]^2- which shows pseudo-octahedrally coordinated fashion, while the counterions are two protonated 1,3-propanediamine in complex 1 and （CsH11N2）^＋ in complex 2. （C5H11N2）＋ is the byproduct of reaction 2, which results from combination of acetonitrile with 1,3-propanediamine. Packing diagrams of the two complexes are also different. There is anti-parallel-aligned-double-meso-bilayer unit in complex 1. However there are four chiral anions arranged in anticlockwise orientation in complex 2.     

New Approach to Synthesis of 6,7—Dimethoxyisatin

A new approach to synthesis of 6,7-dimethoxyisatin is reported.2-nitro-3,4-dimethoxy mandelonitrile in glacial acetic acid was treated with the solution of stannous chloride in hydrochloric acid to give 6,7-dimethoxyisatin in a high yield.     

A New Approach for Asymmetric Synthesis of （-）-Umbelactone

A concise and efficient total synthesis of (-)-umbelactone 1, an occurring γ-hydroxymethyl-α, β-butenolide from Memycelon umbelatum Burro, is described. The synthesis features the use of a ring closing metathesis strategy.