Showing papers on "Diazomethane published in 1989"

p-Nitrophenyl 3-diazopyruvate and diazopyruvamides, a new family of photoactivatable cross-linking bioprobes.

Abstract: p-Nitrophenyl 3-diazopyruvate (DAPpNP) has been developed as a heterobifunctional cross-linking agent for synthesis of photoaffinity probes and photoactivatable cross-linking agents that are nucleophile specific. p-Nitrophenyl chloroglyoxylate is formed in high yield from oxalyl chloride and p-nitrophenol. Subsequent reaction with diazomethane produces DAPpNP in 50-60% overall yield. DAPpNP acylates primary and secondary amines to form 3-diazopyruvamides in high yields. 3-Diazopyruvamide derivatives have been formed from a wide variety of amines including aromatic amines, amino acids, and peptides. 3-Diazopyruvamides undergo photolysis and Wolff rearrangement at 300 nm to produce a ketene amide, which efficiently acylates nucleophilic species to form malonic acid amide derivatives. A family of photoactivatable 3-diazopyruvamide cross-linking agents was synthesized from amino acids. A cleavable, thiol-specific photoactivatable cross-linking agent was synthesized from cystamine. These reagents were caused to react with rabbit muscle aldolase to form mainly dimeric cross-linked species.

Synthesis of cis and trans Whisky and Cognac lactones by the regiocontrolled alkylation of 2‐(trimethylsiloxy)furan

Abstract: The racemic cis- and trans-5-butyltetrahydro-4-methylfuran-2-ones ( = whisky lactones) and their higher homologues tetrahydro-4-methyl-5-pentylfuran-2-ones ( = cognac lactones) have been prepared in 2–3 steps from 2-(trimethylsiloxy)furan. Regioselective alkylation of the latter afforded the 5-butyl- and 5-pentylfuran-2(5H)-ones which served as precursors for the stereocontrolled construction of either diastereoisomer of the beverage lactones. The structure and tautomerization of the diazomethane adducts of these 5-alkylfuran-2(5H)-ones are also described.

Abietane diterpenes with antibiotic activity from the flowers of Salviacanariensis. Reaction of galdosol with diazomethane

Abstract: The new diterpenes canariquinone (9), rosmaquinone (10), and 11-acetoxycarnosic acid (6), together with the already known 7-ethoxyrosmanol (1), 7-methoxyrosmanol (2), and rosmanol (3), were isolate...

Detection of bacterial lipoic acid. A modified gas-chromatographic-mass-spectrometric procedure.

Abstract: The detection of bacterial lipoic acid by a modified g.c.-m.s. procedure is reported. Cells were hydrolysed in HCl to release protein-bound lipoic acid, which, after extraction into benzene, was reduced with NaBH4. The dihydrolipic acid so generated was then isolated by covalent chromatography on dithiolspecific p-aminophenylarsenoxide-agarose and, after elution by 2,3-dimercaptopropane-1-sulphonic acid and extraction into benzene, was allowed to O2-oxidize to the disulphide form. The isolated lipoic acid was allowed to react with diazomethane, and the methyl ester so produced was detected by g.c.-m.s. Analysis of the mass spectrum showed the characteristic molecular ion and seven fragmentation ions, which, along with the identification of those ions retaining the two sulphur atoms, allows the definitive detection of lipoic acid. The methodology has been successfully tested with authentic lipoic acid, the 2-oxoglutarate dehydrogenase multienzyme complex and with whole cells of Escherichia coli. In addition, it has been used to search for and identify lipoic acid in the archaebacterium Halobacterium halobium. The significance of this discovery and the possible roles of the cofactor in H. halobium are discussed.

Steroid catechol degradation: disecoandrostane intermediates accumulated by Pseudomonas transposon mutant strains.

Abstract: SUMMARY: Eleven transposon mutant strains affected in bile acid catabolism were each found to form yellow, muconic-like intermediates from bile acids. To characterize these unstable intermediates, media from the growth of one of these mutants with deoxycholic acid was treated with ammonia, then the crude product was methylated with diazomethane. Four compounds were subsequently isolated; spectral evidence suggested that they were methyl 12α-hydroxy-3-oxo-23,24-dinorchola-1,4-dien-22-oate, methyl 4-aza-12β-hydroxy-9(10)-secoandrosta-1,3,5-triene-9,17-dione-3-carboxylate, methyl 4-aza-9α, 12β-dihydroxy-9(10)-secoandrosta-1,3,5-trien-17-one-3-carboxylate and 4α-[3′-propionic acid]-5-amino-7β-hydroxy-7aβ-methyl-3aα,4,7,7a-tetra-hydro-1-indanone-δ-lactam. It is proposed that the mutants are blocked in the utilization of such muconic-like compounds as the 3,12β-dihydroxy-5,9,17-trioxo-4(5),9(10)-disecoandrosta-1(10),2-dien-4-oic acid formed from deoxycholic acid. A further mutant was examined, which converted deoxycholic acid to 12α-hydroxyandrosta-1,4-dien-3,17-dione, but accumulated yellow products from steroids which lacked a 12α-hydroxy function, such as chenodeoxycholic acid. The products from the latter acid were treated as above; spectral evidence suggested that the two compounds isolated were methyl 4-aza-7-hydroxy-9(10)-secoandrosta-1,3,5-triene-9,17-dione-3-carboxylate and 4α-[1′α-hydroxy-3′-propionic acid]-5-amino-7aβ-methyl-3aa,4,7,7a-tetrahydro-1-indanone-δ-lactam.

Preparation of (chloromethyl)palladium(II) derivatives from complexes of palladium dichloride by reaction with diazomethane or bis(chloromethyl)mercury

Abstract: Treatment, with diazomethane, of a range of palladium dichloride and dibromide complexes containing chelating ligands has been examined. With all but one, the formation of a mono(halogenomethyl) product was observed. The methylene insertion products from complexes of palladium dichloride are relatively stable if at least one olefin or phosphine ligand is present, but with bis-amine or -sulphide ligands the insertion products could not be isolated. However, all of the insertion products showed at least some tendency to revert to the starting dichloro complexes by loss of the methylene moiety. Products of insertion into a Pd–Br bond are less readily formed than those of the corresponding chloride and the resulting bromomethyl derivatives are less stable than their chloromethyl analogues. Chloromethyl derivatives were also prepared from the dichloride by treatment with bis(chloromethyl)mercury (only one of the two chloromethyl groups is transferred) or from a preformed chloromethyl complex by ligand exchange.

Evidence for .alpha.-phosphanyl-.alpha.'-sulfinylcarbene to .alpha.-phosphoranyl-.alpha.'-sulfanylcarbene rearrangement. Synthesis of 2-oxo- and 2-thioxo-1,2-.lambda.5-azaphosphetanes

Abstract: [Bis(diisopropylamino)phosphanyl](trimethylsilyl)diazomethane reacts with p-toluenesulfinyl chloride and p-toluenesulfonyl chloride, affording the same 2-oxo-1,2― 5 -azaphosphetane in 85 and 80 % yield, respectively. These results are rationalized by the transient formation of α-phosphanyl-α'-sulfinylcarbene, which rearranges into α-phosphoranyl-α'-sulfanylcarbene via an intramolecular Wittig-type reaction involving the multiple-bond character of phosphanylcarbenes. [Bis(diisopropylamino)thioxophosphoranyl](trimethylsilyl)diazomethane reacts with p-tolylsulfanyl chloride, giving 2-thioxo-1,2― 5 -azaphosphetane in 86 % yield.

Reactions of diazoalkanes with unsaturated compounds: 6. Catalytic cyclopropanation of unsaturated hydrocarbons and their derivatives with diazomethane

Abstract: A systematic study has been conducted of the catalytic reaction of diazomethane with cyclic and polycyclic unsaturated hydrocarbons, conjugated dienes, as well as with a series of functionalized unsaturated compounds. The feasibility of using transition metal, nontransition metal, and rare earth metal compounds of, for example, Co, Ni, Zr, Cr, Rh, and Dy, has been demonstrated for the first time. It has also been established that Pd(acac)2 has very high activity as a catalyst for the cyclopropanation of terminal and endocyclic double bonds by diazomethane, and that its activity is reduced upon the introduction of n-donor ligands or in the presence of strong polar solvents.

Attempting to monitor the incorporation of deuterium into indole-3-acetic acid and tryptophan in Zea mays grown on deuterium oxide labeled water

Abstract: We are attempting to determine when seedlings of Zea mays sweet corn, var Silver Queen begin de novo biosynthesis of tryptophan and indole-3-acetic acid (IAA) We wish to use the general precursor, deuterium labeled water, to minimize assumptions as to the biosynthetic route Protium in positions 2, 4, 5, 6 7 of the indole ring are non-exchangeable IAA and tryptophan synthesized via the shikimic acid pathway would contain deuterium in one or more of these positions The protium on the indene nitrogen, the carboxyl, the amino group, or the protium alpha to the carboxyl exchange readily and so are removed prior to analysis by base catalyzed exchange The IAA, or trypotophan, is then purified by DEAE, Dowex 50, and two HPLC steps IAA is methylated with diazomethane and analyzed by GC/MS Trytophan is acetylated with triethylamine-acetic anhydride and then methylated with diazomethane and analyzed by GC/MS Results of these studies on plants grown for varying lengths of time and under various light and nutrient conditions will be reported

Synthesis of [21‐14C]‐fusarin C by enzymic demethylation and remethylation with [14C]‐diazomethane

Abstract: Fusarin C, a potent mutagen isolated from Fusariummoniliforme culture extracts, has been prepared radiolabeled in two steps by enzymic hydrolysis of the 21-methyl ester group, using phenobarbital induced microsomal preparations, followed by remethylation using [14C]-diazomethane. Yields, based upon fusarin C, were essentially quantitative and approximately 10% of the [14C]-methyl-nitrosourea, converted to diazomethane, reacted to yield [14C]-fusarin C.

Thermal rearrangement of 4-cyano-2,3-dihydro-5-ethoxy-3-methyl-3-(4-oxo-4H-1- benzopyran-3-yl)furans: a reversed alkoxycarbonylcyclopropane → 5-alkoxy-2,3-dihydrofuran transformation

Abstract: The title dihydrofurans (3f, R1= H, Me, and Cl), prepared from the α-cyano-ester (1e) and diazomethane, thermally rearrange to the cyclopropanes (4f) in predominantly Z-isomeric form.

Umsetzungen kondensierter 2,3-Dihydro-3-thioxo-isothiazol-1,1-dioxide mit Diazomethan sowie Diazoethan Reactions of Condensed 2,3-Dihydro-3-thioxo-isothiazole 1,1-Dioxides with Diazomethane and Diazoethane

Abstract: In einer fruheren Mitteilung konnten wir daruber berichten, das 2,3-Dihydro-3-thioxo-benzisothiazol-1,1-dioxid (Thiosaccharin) mit uberschussigem Diazomethan in Diethylether uber 2,3-Dihydro-2-methyl-3-thioxobenzisothiazol-1,1-dioxid zum 2,3-Dihydro-2-methyl-3-methylen-benzisothiazol-1,1-dioxid reagiert1).

Zur Reaktion von „Pyrazolonblau”︁ mit Diazomethan

Abstract: About the Reaction of „Pyrazolone Blue” with Diazomethane The reaction of “pyrazolone blue” with diazomethane was investigated. A pyridazinone derivative 3, a heterocyclic spiro-cyclopropyl product 4 and a compound 7, which contains three pyrazolone and two diazomethane entities, are formed. 3 reacts with an excess of diazomethane to the methoxy derivative 6. The spiro-cyclopropyl compound 4 is not stable and isomerizes to the corresponding 4,4′-methylidene-bispyrazolone 5. The structures of the products were established by spectroscopic methods and X-ray analysis.

Novel amino acid derivative, its production and use thereof

Abstract: NEW MATERIAL:The amino acid derivative expressed by formula I (R is H or organic group eliminable under reducing or oxidizing condition; R is H or carboxyl-protecting group; R is H or OH-protecting group) wherein the steric configuration of 3-site is (S)-configuration. EXAMPLE:Methyl-(2S,3S)-3-acetoxypyroglutamate. USE:A drug. A synthetic intermediate for novel carbapenam or carbapenem of formula II (R =R ; R is ethyl, i-propyl, etc.) useful as various drugs such as beta-hydroxyglutamic acid acting to cerebral nerve and expected to be useful as a remedy for cerebronervous system or beta-lactam substance having excellent antibacterial activity. PREPARATION:A compound of formula I wherein the configuration of 2-site is (S) can be produced by producing a pyrrolidone derivative of formula II (R is H or CH3) having (S) configuration at 4-site from L-malic acid, cooling the derivative to -78 deg.C and reacting successively with O3 and diazomethane to effect oxidative cleavage reaction.

Pyridinecarboxylic acid ester and selective herbicide

Abstract: NEW MATERIAL:Methyl 6-[4, 5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imi dazol2-yl]-3,4-dihydro-2H-pyrano[3,2-b]pyridine-7-carboxylate. USE:A selective herbicide for wheat-oats. PREPARATION:A pyridinecarboxylic acid expressed by formula II is treated with methanol in an acid catalyst, or treated with diazomethane in an inert solvent, or treated, as necessary, in the presence of a base, with methyl iodide, methyl chloride, methyl bromide, dimethyl sulfate or trimethyloxonium tetrafluoroborate.

Mass spectral evidence for Δ1‐ pyramlines from the 1,3‐dipolar addition of diazomethane to 1‐hydroxy‐2‐naphthoic acid and its methyl ester

Abstract: Mass Spectral Evidence for △ 1 -Pyrazolines from the 1,3-Dipolar Addition of Diazomethane to 1-Hydroxy-2-Naphthoic Acid and Its Methyl Ester