Showing papers on "Diazomethane published in 1982"
TL;DR: Trimethylsilyldiazomethane (TMSCHN2) as mentioned in this paper can be used as a stable and safe substitute for hazardous DMDs, and it is shown that it can be homologated in the presence of trifluoride etherate.
Abstract: Trimethylsilyldiazomethane (TMSCHN2) easily reacts with various ketones in the presence of boron trifluoride etherate in methylene chloride solution to give chain- or ring-homologated ketones, and can be used as a stable and safe substitute for hazardous diazomethane. The reaction proceeds below 0°C during 1-4h, and permits much more efficient homologation than can be achieved with diazomethane.
40 citations
TL;DR: The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1061 as mentioned in this paper, 1061] and the full manuscript of the complete manuscript appeared in:
Abstract: The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1061. DOI:10.1002/anie.198210610
38 citations
TL;DR: In this article, the insertion of diazomethane into the acylselenium linkage of selenoesters 1a − 1f and selenocarbonate 1g afforded the corrresponding ketones 2a − 2f and the ester 2g, respectively, as the chief products.
29 citations
TL;DR: In this paper, the reaction of dimethylsulphoxonium methylide with quaternized derivatives of phenolic Mannich bases, and in certain cases with the bases themselves, constitutes a useful synthesis of dihydrobenzofurans.
Abstract: Reaction of dimethylsulphoxonium methylide with quaternized derivatives of phenolic Mannich bases, and in certain cases with the bases themselves, constitutes a useful synthesis of dihydrobenzofurans. On the other hand treatment of those same quaternized derivatives with diazomethane may be a useful alternative procedure for the preparation of coumarans with base-sensitive groups.
28 citations
24 citations
TL;DR: In this article, diazomethane was added to 2-azido-2-alkenoates and pyrolysis of the resulting pyrazoline derivatives affords the title compounds.
22 citations
TL;DR: In this article, a gas-liquid chromatographic method was used for the analysis of 22 amino acids including asparagine and glutamine in serum, including leucine, isoleucine and tyrosine.
20 citations
TL;DR: It is suggested that 3-hydroxy and 3-keto-3-phenylpropionic acids, which are also endogenous in horse urine, have arisen by an addition of a 2 carbon fragment to benzoyl CoA, in a sequence analogous to the reactions of fatty acid biosynthesis.
16 citations
TL;DR: In this paper, Thiono et al. investigated the reaction of tetrathiooxaliaure-dimethyl dithiooxalate (6) with diazo compounds.
Abstract: Tetrathiooxalsaure-dimethylester (1) bildet mit allen untersuchten Diazoverbindungen 2 in einheitlicher Reaktion die 1,3-Dithiole 3. Komplexe Produktgemische entstehen hingegen bei der Umsetzung von Dithiooxalsaure-O, O-dimethylester (6) mit Diazoverbindungen. Naher untersucht wurde die Reaktion von 6 mit Diazomethan, Diazoethan, 2-Diazopropan und Diphenyl-diazomethan.
Thiono and Dithio Esters, XXIX. Reactions of Diazo Compounds with Thiooxalates
Dimethyl tetrathiooxalate (1) reacts with all diazo compounds 2 investigated to form 1,3-dithioles 3 in high yield. Complex mixtures of products, however, are obtained from O,O-dimethyl dithiooxalate (6) and diazo compounds. The reactions of 6 with diazomethane, diazoethane, 2-diazopropane and diphenyldiazomethane were investigated more in detail.
14 citations
TL;DR: A short synthesis of 9-deoxy-6,9α-methanoepoxy-Δ5-prostaglandin F1(14) from bicyclo[3.2.0]heptan-6-one (3) is described in this paper.
Abstract: A short synthesis of 9-deoxy-6,9α-methanoepoxy-Δ5-prostaglandin F1(14) from bicyclo[3.2.0]heptan-6-one (3) is described. The ketone (3) can be converted by known methods into the vinyl ether (8). In the presence of mercury(II) acetate at 100 °C, the 5-hydroxyalk-1-enyl methyl ether (8) undergoes a novel intramolecular vinyl transetherification reaction to give the Δ2-dihydropyran (9). Hydroboration–oxidation of the dihydropyran (9) furnished selectively the tetrahydropyran-3-ol (10). Subsequent elaboration via oxidation, Wittig olefination, and deprotection afforded 9-deoxy-6,9α-methanoepoxy-Δ5-prostaglandin F1(14). The protected bicyclo[3.2.0] heptan-6-one (16) underwent a ring expansion with diazomethane, producing a 1 : 1 mixture of the two homologated ketones (17) and (18). Wittig olefination and deprotection of these ketones provided 15-epi-9-deoxy-6,9α-methano-Δ5-prostaglandin F1(19) and its structural isomer (20). The two bicyclo[3.2.0]heptan-6-ones (3) and (4) also led directly to a series of 9-deoxy-6,9α-cycloprostaglandins F1via Wittig reactions.
13 citations
TL;DR: In this paper, it was shown that the stereoselectivity of the diazomethane reaction is mainly controlled by the attractive, electrostatic force between the DMD and a neighbouring, axial oxygen or the axial lone-pair electrons of O-5 in the transition state.
TL;DR: A liquid chromatographic method was developed for the simultaneous determination of penta- and tetrachlorophenols in urine and does not involve the use of such potentially dangerous compounds as benzene, diazomethane or pyridine.
TL;DR: In this article, the resolution of DL-myo-inositol 1-phosphate and other sugar enantiomers by gas chromatography (GC) is discussed, and the derivation procedures for trimethylsilyl-methylphosphates (TMS-Me), heptafluorobutyric (HFB) esters, and cyclic alkaneboronic esters are discussed.
Abstract: Publisher Summary This chapter focuses on the resolution of DL-myo-inositol 1-phosphate and other sugar enantiomers by gas chromatography (GC). Enantiomeric amino acids, 2-amino-l-phenylethanols, and lactic acid are separated as simple derivatives by GC on a glass capillary column coated with a chiral liquid phase. The phase consists of N - t -butyl-L-valinamide in α-amide linkage with a copolymer of dimethylsiloxane and a carboxyalkyl-methylsiloxane. The chapter discusses the derivation procedures for trimethylsilyl-methylphosphate (TMS-Me), heptafluorobutyric (HFB) esters, and cyclic alkaneboronic esters. TMS-Me derivatives of inositol phosphates are prepared by complete trimethylsilylation of the molecules, followed by the methanolysis of the phosphate trimethylsilyl (TMS) ester moiety and then reaction with diazomethane. The Chirasil-Val column is also suitable for GC-MS. The original applications of Chirasil-Val are with nitrogen-containing substances and stressed the role of the nitrogen atoms in the achievement of chiral separations. DL-Glucose is best separated on a 20-meter column as the methaneboronate coderivatized with a trimethylsilyl group or as the butaneborcnate coderivatized with TMS or HFB moiety.
TL;DR: This work demonstrates that chemical ionization-mass spectrometic techniques can be a labor-saving alternative to other methods of structure determination and that 3α,7α,12α,25-tetrahydroxy-5β-cholestan-24-one is probably an intermediate in the 25-hydroxylation pathway of cholic acid from cholesterol.
TL;DR: In this paper, the 4- O -methyl derivatives were obtained by treatment of 4 and 5 with diazomethane in the presence of boron trifluoride etherate.
TL;DR: In this article, 2-Mesitylenesulfonyldiazomethane (4) was conveniently prepared from 2-mesitylenes sulfonylchloride (5) in 4 steps.
Abstract: 2-Mesitylenesulfonyldiazomethane (4) was conveniently prepared from 2-mesitylenesulfonylchloride (5) in 4 steps. Reaction of 4 with benzoyl chloride smoothly furnished α-benzoyl α-(2-mesitylenesulfonyl) diazomethane (9). Thermal treatment of 9 in the presence of alcohols generally gave the Wolff rearrangement product (10) as the major product accompanied with the intramolecular C-H insertion product (11). When acetonitrile was used as a reaction solvent, a substantial amount of the desulfonylated product (13) was also formed.
TL;DR: In this paper, the use of Claisen rearrangements on 1-methallyloxy-5methoxyantraquinone (9) and 1-(2′-methylene-4′-pentenoxy)-5 methoxycline (2methoxyanthraquinones) was studied for the synthesis of anthracycline antibiotics.
TL;DR: In synthesis of PTA2, the commercially available (–)-myrtenal underwent smooth 1,4- addition with the mixed cuprate to afford the adlehyde 3, which can be converted quantitatively to the aldehyde 5 by the action of Hg(OAc)2-KI in aqueous tetrahydrofuran.
Abstract: Publisher Summary This chapter discusses the synthesis of pinane thromboxane (PTA2) and carbocyclic thromboxane A2 (CTA2), two stable and biologically active structural analogs of thromboxane A2 (TxA2) In synthesis of PTA2, the commercially available (–)-myrtenal underwent smooth 1,4- addition with the mixed cuprate to afford the adlehyde 3 Reaction of 3 with methoxymethylenetriphenylphosphorane in toluene-tetrahydrofuran solution furnished the enol ether 4 which can be converted quantitatively to the aldehyde 5 by the action of Hg(OAc)2-KI in aqueous tetrahydrofuran The top side chain can be completed by a Wittig reaction employing the sodium salt of 4-carboxybutylidenetriphenylphosphorane in dimethyl sulfoxide, leading after diazomethane treatment to the methyl ester 6 in 80% yield Deprotection of the hydroxy group by exposure to acetic acid-water-tetrahydrofuran at 45° led to the methyl esters 11 and 15, which are separated by preparative thin-layer chromatography or flash column chromatography Hydrolysis of the more polar isomer (11) with lithium hydroxide in aqueous tetrahydrofuran led to PTA2 (12) in quantitative yield The synthesis of carbocyclic thromboxane A2 (CTA2) starts with 2-formylbicyclo[ 311]hept-2-ene (2)5 and proceeds along similar lines as for the preparation of PTA2
TL;DR: In this paper, the 3-fluoro-2-hydroxynitriles I a−h were found to be versatile intermediates to the 3fluoropyruvic acids II a-h via a new method for the synthesis of these important compounds.
TL;DR: In this article, a ring enlargement of [2.2]metacyclophane-1,10-dione with diazomethane conveniently affords [3.3]-metacy clophanes.
Abstract: Ring enlargement of [2.2]metacyclophane-1,10-dione (1) with diazomethane conveniently affords [3.2] and [3.3]-metacyclophanes. The homologues [3.2]metacyclophane-1,11- and -2,11-diones (2a and b), thus obtained, were used for the synthesis of [3.2]metacyclophane-1,10-diene (5) and the parent hydrocarbon [3.2] metacyclophane (4). [3.3] Metacyclophane-1,12-, -1,11-, and -2,11-diones (6a-c), prepared by regioselective carbene insertion into (2a) and (2b) with diazomethane, served as intermediates in the synthesis of [3.3]metacyclophane (8). The reactivity of the carbonyl groups of oxometacyclophanes decreases with ring size and thus correlates with ring strain. In contrast to (6a-c), the [3.2]metacyclophanediones (2a and b) form hemiacetals when dissolved in methanol.
Patent•
20 Feb 1982
TL;DR: The 3,7-dimethyl-2-octene-1,8-dioic acid of formula 7 and formula 8, and its ester as mentioned in this paper was used as a sex pheromone of bean weevils.
Abstract: NEW MATERIAL:The 3,7-dimethyl-2-octene-1,8-dioic acid of formula 7 and formula 8, and its ester. USE:A sex pheromone of bean weevils. The compound is also expected as an intermediate for various pharmaceuticals, pesticides, perfumes, etc. PROCESS:The compound of formula 7 or 8 can be obtaied by extracting the excreta of Callosobruchus chinensis Linne (esp. female) with ether, or synthesized from geranyl acetate of formula 1 (Ac is acetyl) via the compounds of formulas 2-6. The reaction of the compound of formula 7 or 8 with a lower alcohol or diazomethane, etc. affords its lower alkyl ester.
TL;DR: A method is described for measuring (-)-threo-chlorocitric acid in human plasma using a calibration curve and the residue after removal of the ethyl acetate is treated with ethereal diazomethane.
TL;DR: In this paper, a method for the determination of 3,6-dichloropicolinic acid in sugar beets using a gas chromatographic method with either a capillary column and electron capture detection or a packed column and a Hall electrolytic conductivity detector was described.
TL;DR: In this paper, a novel 1-Imino-1λ4,2,4,6,6-thiatriazine 9c was cyclisized with N-arylsulfonyl sulfinyl amines 4a-c to 1λ 4, 2, 4, 6, 6 thiatriazines 9c, and the cyclization mechanism with substituted imido sulfurous diamide intermediate was discussed.
Abstract: Synthesis and Structure of Novel 1-Imino-1λ4,2,4,6-thiatriazines
O,O′-Dimethyldiisobiurete 1 is cyclisized with N-arylsulfonyl sulfinyl amines 4a–c to 1λ4,2,4,6-thiatriazines 9a–c. The reaction with corresponding sulfur diimides 7a–c leads to identical 1λ4,2,4,6-thiatriazines 9a–c. Methylation products from 9c with diazomethane are isolated by column chromatography. The cyclization mechanism with a substituted imido sulfurous diamide intermediate is discussed.
TL;DR: In this article, 2-ethynyl-substituted aziridines were obtained by the reaction of acetylenic β-amino and β-azido alcohols with triphenylphosphine and carbon tetrachloride in the presence of triethylamine.
Abstract: 2-Ethynyl-substituted aziridines were obtained by the reaction of acetylenic β-amino and β-azido alcohols with triphenylphosphine and carbon tetrachloride in the presence of triethylamine. The cycloaddition of carbenes and diazomethane to an acetylenic imine was investigated. 2-Ethynylaziridines were obtained in the case of carbonylalkoxycarbenes. The regioselectivity of the cycloaddition of carbenes to an acetylenic imine is demonstrated.
Journal Article•
TL;DR: In this paper, the structure of pseudolaric acid A and B were established as 1 and 2 respectively by chemical, spectral and X-ray diffraction methods, which was elucidated by 1H NMR spectrum.
Abstract: Tu-Jin-Pi, the bark of Pseudolarix kaempferi, Gord.(Pinaceae) has been used in our country for the treatment of skin diseases caused by fungi. Three novel diterpenic acids, pseudolaric acids A, B, and C were isolated from the bark. The structures of pseudolaric acid A and B were established as 1 and 2 respectively by chemical, spectral and X-ray diffraction methods.Pseudolaric acid A, C_(22)H_(28)O_6, m. p. 218～219℃ and B, C_(23)H_(28)O_8, m. p. 145～146℃. Both acids possess a methyl group attached to a tertiary carbon and a side chain with α β,γ δ-dienoic acid structure which was elucidated by ~1H NMR spectrum. Both acids possess an acetoxy functional group which may be hydrolyzed by aqueous KOH and the free alcohol reacetylated by Ac_2O-pyridine. Both acids possess a lactone ring that is resistant to hydrolysis and it was identified through IR and ~(13)C NMR spectra. The only structural difference between the two acids are located on the following parts: pseudolaric acid A(CH=CCH_3) and B(CH=CCO_2CH_3). By methylation with diazomethane, pseudolaric A forms a methyl ester, while B forms a methyl ester with the addition of another mole of CH_2N_2. The latter was shown to possess the following partial structure:The carbon skeleton was established by X-ray diffraction analysis of pseudolaric acid A. The methyl esters of deacetyl pseudolaric acid A and B were dehydrated readily with thionyl chloride-pyridine. ~1H NMR examinations on these dehydration products with INDOR technique showed that they possess the following partial structure respectively:These results further support the assignment of the structures 1 and 2 for pseudolaric acid A and B.