Formation of cyclic enol ethers from a labile biological precursor: an example of analytical artifacts

Three isomeric enol ethers are among those constituents apparently unique to mouse urine as identified by gas chromatographic analysis. These compounds appear to be artifacts arising from the cyclization and dehydration of 6-hydroxy-6-methyl-3-heptanone. Identification of the trimethylsilyl ether of 6-hydroxy-6-methyl-3-heptanone in the silylated ether extract of mouse urine indicates that the precursor keto alcohol is indeed present in the urine. Since similar heterocyclic compounds are often identified in urine samples analyzed by gas chromatography, formation of various analysis artifacts arising from analogous cyclization and dehydration reactions is likely.     

A major urinary protein of the domestic cat regulates the production of felinine, a putative pheromone precursor

Domestic cats spray urine with species-specific odor for territorial marking. Felinine (2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid), a putative pheromone precursor, is excreted in cat urine. Here, we report that cauxin, a carboxylesterase excreted as a major urinary component, regulates felinine production. In vitro enzyme assays indicated that cauxin hydrolyzed the felinine precursor 3-methylbutanol-cysteinylglycine to felinine and glycine. Cauxin and felinine were excreted age dependently after 3 months of age. The age-dependent increases in cauxin and felinine excretion were significantly correlated. In mature cats, cauxin and felinine levels were sex-dependently correlated and were higher in males than in females. In headspace gas of cat urine, 3-mercapto-3-methyl-1-butanol, 3-mercapto-3-methylbutyl formate, 3-methyl-3-methylthio-1-butanol, and 3-methyl-3-(2-methyldisulfanyl)-1-butanol were identified as candidates for felinine derivatives. These findings demonstrate that cauxin-dependent felinine production is a cat-specific metabolic pathway, and they provide information for the biosynthetic mechanisms of species-specific molecules in mammals.     

Synthesis and bioactivity of optically active forms of 1-methyl-2-cyclohexen-1-ol. An aggregation pheromone of dendroctonus pseudotsugae

Both the enantiomers of 1-methyl-2-cyclohexen-1-ol, an aggregation pheromone of the female Douglas-fir beetle, were synthesized from the enantiomers of seudenol (3-methyl-2-cyclohexen-1-ol). The enantiomers were less active than the racemate of 1-methyl-2-cyclohexen- 1-ol as an aggregation pheromone.     

Application of ion mobility spectrometry for the detection of human urine

The aim of the present study was to evaluate the suitability of ion mobility spectrometry (IMS) for the detection of human urine as an indication of human presence during urban search and rescue operations in collapsed buildings. To this end, IMS with a radioactive ionization source and a multicapillary column was used to detect volatile organic compounds (VOCs) emitted from human urine. A study involving a group of 30 healthy volunteers resulted in the selection of seven volatile species, namely acetone, propanal, 3-methyl-2-butanone, 2-methylpropanal, 4-heptanone, 2-heptanone and octanal, which were detected in all samples. Additionally, a preliminary study on the permeation of urine volatiles through the materials surrounding the voids of collapsed buildings was performed. In this study, quartz sand was used as a representative imitating material. Four compounds, namely 3-methyl-2-butanone, octanal, acetone and 2-heptanone, were found to permeate through the sand layers during all experiments. Moreover, their permeation times were the shortest. Although IMS can be considered as a potential technique suitable for the detection, localization and monitoring of VOCs evolved from human urine, further investigation is necessary prior to selecting field chemical methods for the early location of trapped victims.     

Pheromones of coleoptera. Communication 6. Synthesis of R,Z-14-methyl-8-hexadecenal (cis-trogodermal)

Conclusions The simple synthesis of optically active R,Z-14-methyl-8-hexadecenal (cis-trogodermal), the principal components of the aggregation pheromone ofTrogoderma granarium, was accomplished. The synthesis was based on the use of R-1-bromo-4-methylhexane and Z-4-chloro-2-buten-1-ol as the sources of the chiral and olefin fragments.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 906–910, April, 1987.     

Synthesis of (4R)-Methylnonan-1-ol and (4R,8RS)-Dimethyldecanal from (S)-(+)-3,7-Dimethyl-1,6-octadiene

Optically active (4R,8RS)-dimethyldecanal, an analog of the aggregation pheromone of the flour beetles Tribolium confusum and T. Castaneum, and (4R)-methylnonan-1-ol, the sex pheromone of the yellow mealworm Tenebrio molitor L., are synthesized using ozonolytic transformation of (6R,10)-dimethyl-9-undecen-2-one to (6R)-methyl-9-hydroxynonan-2-one in the key step. The starting compound is available as enantiomerically enriched (ee ~50%) (S)-(+)-3,7-dimethyl-1,6-octadiene.     

Reaction of hexafluoropropylene and its oligomers with acetone oxime

Reactions of perfluoropropylene and its oligomers with acetone oxime in the presence of a base afford perfluoroalkyl and/or perfluoroalkenyl ethers of acetone oxime. When heated to 100 °C, the 3-perfluoro-2-methyl-2-pentenyl ether of acetone oxime (3) is quantitatively converted to 4-hydroxy-3-methyl-5,5-bistrifluoromethyl-4-pentafluoroethyl-1-pyrroline (4), the structure of which was established by X-ray diffraction analysis. A convenient one-stage synthesis of perfluoro-3-isopropyl-4-methyl-3-penten-2-one (7) was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1068–1072, June, 1994.     

Changes in Phenols,Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.     

Evidence for a trianion intermediate in the metalation of 4-hydroxy-6,7-dimethoxy-8-methyl-2-naphthoic acid. Methodology and application to racemic 5,5'-didesisopropyl-5,5'-dialkylapogossypol derivatives

The metalation of 4-hydroxy-6,7-dimethoxy-8-methyl-2-naphthoic acid (8) affording trianion 6 is presented and applied to the regioselective efficient construction of a series of 5,5'-didesisopropyl-5,5'-dialkylapogossypol derivatives 3 that are potent pan-active inhibitors of antiapoptotic Bcl-2 family proteins.     

New 2-methyl-6-alkylamino-5,8-quinolinequinones and 1,2,3,4-tetrahydro derivatives

The syntheses of six new 2-methyl-6-alkylamino-5,8-quinolinequinones, three 1,2,3,4-tetrahydro-5,8-quinolinequinones, and 7-(2′,6′,10′-trimethylundecyl)-6-hydroxy-5,8-quinolinequinone are described as potential antimetabolites of coenzyme Q and as potential antimalarial agents. The six 2-methyl-6-alkylamino-5,8-quinolinequinones were prepared by a six-step synthesis. 2-Methyl-6-methoxy-8-nitroquinoline was prepared from 2-nitro-4-methoxyaniline and crotonaldehyde by a Skraup reaction. Raney nickel reduction gave 2-methyl-6-metboxy-8-aminoquinoline, which upon diazotization followed by dithionite reduction yielded 2-methyl-6-methoxy-5,8-diaminoquinoline. Subsequent dichromate oxidation gave 2-methyl-6-methoxy-5,8-quinolinequinone, which yielded the corresponding 2-methyl-6-alkylamino-5,8-quinolinequinone in good yield when treated with the appropriate alkylamine. The telrahydro-5,8-quinolinequinones were prepared by catalytic hydrogenation of the appropriate 5,8-quinolinequinones at elevated H₂ pressure followed by air oxidation of the reduction product. 7-(2′,6′,10′-Trimethylundecyl)-6-hydroxy-5,8-quinolinequinone was synthesized by radical alkylation of 6-hydroxy-5,8-quinolinequinone by thermal decomposition of di-3,7,11-trimethyldodecanoyl peroxide, which was prepared by a multistep procedure from farnesol. Of the five new 2-methyl-6-alkylamino-5,8-quinoline-quinones tested against P. berghei in mice (blood schizonticidal test), only 2-methyl-6-cycloheptylamino-5,8-quinolinequinone was active (T-C = 6.1 at 320 mg./kg.). Both 7-(2′,6′,10′-trimelhytundecyl)-6-hydroxy-5,8-quinolinequinone and the tetrahydro derivatives were inactive in this same test system.     

Enthalpic changes on mixing two couples of S- and R-enantiomers of heptane-2-ol, octane-2-ol, nonane-2-ol, 3-chloro-propane-1,2-diol, 2-methyl-1,4-butanediol at 298.15 K

Enthalpies of mixing of (R)- and (S)-enantiomers of liquid chiral compounds such as heptane-2-ol, octane-2-ol, nonane-2-ol, 3-chloro-propane-1,2-diol and 2-methyl-1,4-butanediol have been measured over a range of mole fractions at 298.15 K, albeit very small values. Mixing of heterochiral liquids of heptane-2-ol, octane-2-ol, nonane-2-ol, 3-chloro-propane-1,2-diol, realized enthalpic destabilization over the whole range of mole fractions, whereas that of 2-methyl-1,4-butanediol realized enthalpic stabilization over entire compositions. The maximum values of enthalpies of mixing and the intermolecular interaction of cohesive energy density and entropy of vaporization showed a linear correlation except for the compounds having two chiral centers and others.     

Ozonolysis of geraniol-trans, 6-methyl-5-hepten-2-one, and 6-hydroxy-4-methyl-4-hexenal: kinetics and mechanisms

A combined density functional theory and transition-state theory study of the mechanisms and reaction coefficients of gas-phase ozonolysis of geraniol-trans, 6-methyl-5-hepten-2-one, and 6-hydroxy-4-methyl-4-hexenal is presented. The geometries, energies, and harmonic vibrational frequencies of each stationary point were determined by B3LYP/6-31(d,p), MPW1K/cc-pVDZ, and BH&HLYP/cc-pVDZ methods. According to the calculations, the ozone 6-methyl-5-hepten-2-one reaction is faster than the ozone 6-hydroxy-4-methyl-4-hexenal reaction, but both are slower than the ozone geraniol-trans reaction. By using the BH&HLYP/cc-pVDZ data, a global rate coefficient of 5.9 x 10(-16) cm(3) molecule(-1) s(-1) was calculated, corresponding to the sum of geraniol-trans, 6-methyl-5-hepten-2-one, and 6-hydroxy-4-methyl-4-hexenal reactions with the ozone. These results are in good agreement with the experimental studies.     

Reaction of oligomethylene di(3-oxobutanoate) with 1,1-disubstituted alkenes and molecular oxygen in the presence of manganese(II and/or IE) acetate

The reactions of 1,1-disubstituted ethenes with oligomethylene di(3-oxobutanoate) in the presence of manganese(II and/or III) acetate and atmospheric oxygen yielded an ω-(3-oxobutanoyloxy)alkyl 6,6-diaryl-3-hydroxy-3-methyl-1,2-dioxane-4-carboxylate, oligomethylene di(6,6-diaryl-3-hydroxy-3-methyl-1,2-dioxane-4-carboxylate)s, ω-hydroxyalkyl 6,6-diaryl-3-hydroxy-3-methyl-1,2-dioxane-4-carboxylates, an ω-(3-oxobutanoyloxy)alkyl 5,5-diaryl-2-methyl-4,5-dihydrofuran-3-carboxylate, oligomethylene di(5,5-diaryl-2-methyl-4,5-dihydrofuran-3-carboxylate)s, ω-hydroxyalkyl 5,5-diaryl-2-methyl-4,5-dihydrofuran-3-carboxylates, and an ohgomethylene diester bearing a substituted 1,2-dioxane ring and a substituted 4,5-dihydrofuran ring. The reaction of the 1,2-dioxan-3-ols with acid gave the corresponding compounds bearing furan rings. The reaction of 1,1,6,6-tetraaryl-1,5-hexadienes with oligomethylene di(3-oxobutanoate) in the presence of manganese(III) acetate yielded macrocyclic diesters bearing two 4,5-dihydrofuran rings.     

新型套索冠醚-金属离子络合性能的紫外光谱法与质谱法研究

本文合成了3种套索冠醚4、5和6,分别测定了它们与Hg^2^ 、Pb^2^ 、Zn^2^ 、cd^2^ 、Ni^2^ 、Co^2^ 、Cu^2^ 、Ag^ 、Tb^3^ 和Eu^3^ 所形成的络合物的紫外吸收光谱,用电喷雾液相色谱-质谱联用仪分别表征了它们与TB^3^ 形成的络合物,结果显示它们对上述金属离子有很好的络合性。     

Synthesis of certain metabolites and analogs of vitamin B6 and their ring-chain tautomerism

Pyridoxol and pyridoxal on benzylation with dimethylphenylbenzylammonium hydroxide (“leucotrope”) gave 3-O-benzylpyridoxol (IV) and 3-O-benzylpyridoxal (V), respectively. As a possible mechanism of this reaction an ion pair intermediate has been postulated. Oxidation of IV and V with chromic oxide-pyridine-acetic acid complex gave 3-O-benzyl-4-pyridoxic acid lactone (VI), which could also be obtained by benzylation of 4-pyridoxic acid. Treatment of VI with dimethylamine gave 2-methyl-3-benzyloxy-5-hydroxymethylpyridine-4-N,N-dimethylcarbox-amide (X) which oxidized to form the 5-formyl derivative (XI). The latter on hydrolysis yielded the metabolite, 2-methyl-3-hydroxy-5-formylpyridine-4-carboxylic acid (I). When reacted with liquid ammonia, VI gave 3-O-benzyl-4-pyridoxamide (VII) which was then oxidized to give 2-methyl-3-benzyloxypyridine-4,5-dicarboxylic acid cyclicimide(IX). Acid hydrolysis of IX gave another metabolite, 2-methyl-3-hydroxypyridine-4,5-dicarboxylic acid (XIII), which could also be obtained by oxidizing XI with potassium permanganate in water to yield 2-methyl-3-benzyloxy-5-carboxypyridine-4-N,N-dimethylcarboxamide (XII) and subsequent hydrolysis with hydrochloric acid. A positional isomer of I, 2-methyl-3-hydroxy-4-formylpyridine-5-carboxylic acid (XVII) was synthesized starting from 3-O-benzyl-5-pyridoxic acid lactone (XIV) following similar reaction sequences used for the preparation of I. Ring-chain tautomerism has been studied in I, XVII, opianic acid (XVIII), phthalaldehydic acid (XIX) and (2-carboxy-4,5-dimethoxy)-phenylacetaldehyde (XX) in different solvents by nmr and in the solid state by ir spectroscopy. A direct and reliable differentiation between the open form (aldehyde proton in low field) and the ring form (lactol proton in the intermediate field) has been obtained by nmr spectroscopy. In sodium deuteroxide and pyridine-d₅ the open chain form existed exclusively (except for homolog (XX) which is in cyclic form in pyridine-d₅), whereas in 18% hydrogen chloride in deuterium oxide all the compounds are completely in the cyclic form. In hexafluoroacetone hydrate-d₂, XVIII, XIX, and XX exist in the cyclic form whereas I is in the open form. In DMS0-d₆ both cyclic and open-chain forms have been observed in XVIII, XIX and XX. Definite peak assignment for the two forms could not be made in I due to broadening or superimposition with C₆-H. The metabolite I, isometabolite (XVII) and opianic acid (XVIII) form cyclic acetyl derivatives which give a sharp lactol peak. In the solid state XVIII, XIX are in the cyclic form and I and XX in the open-chain form as observed by ir spectroscopy.     

A Chemical Study of Burley Tobacco Flavour (Nicotiana tabacum L.) VII. Identification and synthesis of twelve irregular terpenoids,related to solanone,including 7,8-dioxabicyclo[3.2.1]octane and 4,9-dioxabicyclo[3.3.1]nonane derivatives

Twelve novel constituents isolated from Burley tobacco condensate by semi-preparative GLC. have been identified as (E)-3,4-epoxy-5-isopropyl-nonane-2,8-dione ( A ), exo-(1-methyl-4-isopropyl-7,8-dioxabicyclo[3.2.1]oct-6-yl)methyl ketone ( B ), exo-1-(1-methyl-4-isopropyl-7,8-dioxabicyclo[3.2.1]oct-6-yl)-ethanol ( C ), (E)-5-isopropyl-8-hydroxy-8-methyl-non-6-en-2-one ( D ), (E)-5-isopropyl-6,7-epoxy-8-hydroxy-8-methyl-nonan-2-one ( E ), endo-2-(1-methyl-4-isopropyl-7,8-dioxabicyclo[3.2.1]oct-6-yl)-propan-2-ol ( F ), 3,3,5-trimethyl-8-isopropyl-4,9-dioxabicyclo[3.3.1]nonan-2-ol ( G ), (E)-5-isopropyl-non-3-ene-2,8-diol ( H ), 5-isopropyl-nonane-2,8-diol ( I ), (E)-5-isopropyl-8-hydroxy-non-6-en-2-one ( J ), 5-isopropyl-8-hydroxy-nonan-2-one ( K ), and (E)-3-isopropyl-6-methyl-hepta-4,6-dien-1-ol ( L ). Compounds A–K were synthesized from norsolanadione ( 2 ), and compound L from 2-isopropyl-5-oxo-hexanal ( 15 ). The relative configuration of the bicyclic internal acetals B, C, F, G and their δ-keto-epoxide precursors A and E is discussed. All these Burley tobacco flavour components belong to a growing family of metabolites structurally related to solanone ( 1 ). They are believed to arise from the breakdown of cembrene-type precursors.     

Calorimetric investigations on the action of alarm pheromones in the hornet Vespa crabro

This study investigated the effects of alarm pheromone components on the heat production rates of hornets (Vespa crabro) by means of direct calorimetry. In a flow-through system, pheromones from hornets, honeybees (Apis mellifera) and yellowjackets (Vespula vulgaris) were sucked through a measuring vessel containing a group of hornet workers. The locomotive reaction of hornet workers was recorded as an increase of the heat production rate. Hornets exhibited a strong response to their own alarm pheromone components, mainly 2-methyl-3-butene-2-ol (MBO). They also reacted intensively upon the main alarm pheromone component of the honey bee, isopentylactetate (IPA), but less pronounced to alarm pheromone components of yellowjackets. The metabolic response of hornets to MBO was dose-dependent. The heat production rates of provoked hornet workers were similar to those of flying hornets. (z)-9-Pentacosene, a substance which is believed to be a thermoregulative brood pheromone, induced no metabolic reaction.     

Iodocyclization of N,N-dialkylamino-2-methyl-4-penten-2-ol oxides

It is shown that in the iodination of N,N-dialkylamino-2-methyl-4-penten-2-ol and N,N-diethylamino-3-butene oxides the N-oxide group participates in the intramolecular cyclization of these compounds. N,N-Dialkyl-4-methyl-4-hydroxy-6-iodomethyltetrahydro-1,2-oxazine iodides were obtained by iodination of the former, whereas the latter under similar conditions gives N,N-diethyl-5-iodomethyltetrahydro-1,2-oxazolinium iodide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1340–1343, October, 1976.     

Efficient synthesis of 3,3′,5,5′-tetra(p-X-phenylethynyl)biphenyl (X: NMe2; OMe) by homocoupling of 1-bromo-3,5-di(p-X-phenylethynyl)benzene or by heterocoupling of 3,3′,5,5′-tetraethynylbiphenyl with p-X-phenylbromobenzene with nickel or palladium complexes, respectively

The conjugated 3,3′,5,5′-tetra(p-X-phenylethynyl)biphenyl derivatives were efficiently obtained by homocoupling of 1-bromo-3,5-di(p-X-phenylethynyl)benzene mediated by zero-valent nickel complexes.The 1-bromo-3,5-di(p-X-phenylethynyl)benzene was previously prepared by heterocoupling between 1-bromo-3,5-di(ethynyl)benzene and p-X-iodobenzene (X: NMe₂; OMe) catalysed by the palladium/copper system in good yield. The necessary 1-bromo-3,5-di(ethynyl)benzene was obtained by heterocoupling between 1,3,5-tribromobenzene and 2-methyl-3-butyn-2-ol catalysed by palladium and successive treatment with sodium hydroxide in dry toluene, in good yield.The same 3,3′,5,5′-tetra(p-X-phenylethynyl)biphenyl (X: NMe₂; OMe) derivatives were alternatively synthesised in highest yield by heterocoupling between 3,3′,5,5′-tetra(ethynyl)biphenyl and p-X-bromobenzene (X: NMe₂; OMe) catalysed by palladium in excellent yields. Previously, 3,3′,5,5′-tetra(ethynyl)biphenyl was obtained in practically quantitative yield by homocoupling of 1-bromo-3,5-di[4-(2-methyl-3-butyn-2-ol)] benzene mediated by the zero-valent nickel complex to the 3,3′,5,5′-tetra{di[4-(2-methyl-3-butyn-2-ol)]}biphenyl followed the treatment with sodium hydroxide.     

Synthesis of New 3-Phenoxypropan-2-ols with Various Heterocyclic Substituents

1-Phenoxy-3-piperidinopropan-2-ol, 1-(5-methyl-1,3-benzothiazol-2-ylsulfanyl)-3-phenoxypropan-2-ol, 1-(2-hydroxy-3-phenoxypropyl)azepan-2-one, 1,1′-(6-chloro-1,3-benzothiazol-2-ylimino)bis(3-phenoxypropan-2-ol), 1-(1,3-benzothiazol-2-ylsulfanyl)-3-phenoxypropan-2-ol, 1,1′-(piperazine-1,4-diyl)bis(3-phenoxypropan-2-ol), and 1,3-bis(2-hydroxy-3-phenoxypropyl)barbituric acid were synthesized by condensation of 1,2-epoxy-3-phenoxypropane with the corresponding amines and thiols.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 70–72.Original Russian Text Copyright © 2005 by Mesropyan, Ambartsumyan, Avetisyan, Galstyan, Arutyunova.