bluuebunny/crossref_metadata_2025 huggingface dataset:
Decreased lactation capacity and altered milk composition in insulin receptor substrate null mice is associated with decreased maternal body mass and reduced insulin-dependent phosphorylation of mammary Akt
Authors: Hadsell Darryl L , Olea Walter , Lawrence Nicole , George Jessy , Torres Daniel , Kadowaki Takahashi , Lee Adrian V
Published: July 2007

Expression of insulin receptor substrates (IRS)-1 and -2 within the mammary gland was found to be high at mid-lactation and dramatically decreased with mammary involution. This observation supports the hypothesis that these proteins are induced in the mammary gland with lactogenesis and involved in normal milk synthesis. To test this hypothesis, lactation capacity, along with indices of mammary secretory cell glucose metabolism and cell signaling were compared in normal mice and mice carrying targeted mutations in either the Irs1 or Irs2 genes. Mammary IRS-1 and IRS-2 protein levels were increased within 1 day of parturition and reached maximal levels by 5 days post partum. Dams carrying germline mutations of Irs1 or Irs2 displayed reduced lactation capacity as assessed by weight gain of pup litters. The reduction was more dramatic in Irs1−/− versus Irs2−/− dams. Maternal body weight was also reduced in Irs1−/− dams as well as in Irs1+/− Irs2+/− dams. The loss of IRS-1 had little impact on mammary gland expression of milk protein mRNAs, glucose transport, or on the abundance and subcellular localization of hexokinases I and II. The loss of IRS-1 was associated with a compensatory increase in insulin-induced IRS-2 phosphorylation; however, the loss of IRS-1 did also cause a reduction in insulin-dependent mammary gland-specific activation of Akt phosphorylation. These results support the conclusion that IRS-1 is important for insulin-dependent activation of Akt signaling within the lactating mammary gland, but that loss of this protein has only modest impact on normal milk synthesis, since related signaling proteins such as IRS-2 may act in compensatory fashion.
Production of recombinant channel catfish (Ictalurus punctatus) FSH and LH in S2 Drosophila cell line and an indication of their different actions
Authors: Zmora Nilli , Kazeto Yukinori , Kumar R Sampath , Schulz Rüdiger W , Trant John M
Published: July 2007

Due to the lack of purified, native gonadotropins (GtH) for almost all species of fish, we designed a system for the production of recombinant bioactive luteinizing hormone (LH) and follicle stimulating hormone (FSH) using the channel catfish (Ictalurus punctatus) as a model animal. The strategy was to produce the three subunits composing FSH and LH, i.e. the common α-subunit (α-glycoprotein hormone (α-GP)), β-FSH, and β-LH subunit, individually in stable recombinant insect cells (S2) with C-terminal His-tag. This expression system was also used to co-express the α-subunit without the His-tag with each of the His-tagged β-subunits. The recombinant S2 cells were capable of secreting FSH and LH heterodimers and α-GP in abundance; however, expression of the individual β-subunits was much less successful. The recombinant GtHs were partially purified from the cell medium by immobilized metal affinity chromatography to ~15% purity with a yield of 7 and 4 mg per liter of medium for FSH and LH respectively. These recombinant GtHs activated their receptors in vitro, enhanced estrogen secretion, up-regulated several steroidogenic enzyme genes in channel catfish ovarian follicles, and increased androgen secretion from African catfish testis. Interestingly, the FSH and LH dose–response curves for each of these biological activities clearly demonstrate differences in their cellular action and physiological roles. This expression system may be an important development for the production of species-specific GtHs so that FSH- and LH-specific mechanisms of actions within the reproductive endocrine processes can finally be examined with homologous, albeit recombinant, hormones.
Bacterial Community Changes during Plant Establishment at the San Pedro River Mine Tailings Site
Authors: Rosario Karyna , Iverson Sadie L. , Henderson David A. , Chartrand Shawna , McKeon Casey , Glenn Edward P. , Maier Raina M.
Published: July 2007

Mine tailings are moderately to severely impacted sites that lack normal plant cover, soil structure and development, and the associated microbial community. In arid and semiarid environments, tailings and their associated contaminants are prone to eolian dispersion and water erosion, thus becoming sources of metal contamination. One approach to minimize or eliminate these processes is to establish a permanent vegetation cover on tailings piles. Here we report a revegetation trial conducted at a moderately impacted mine tailings site in southern Arizona. A salt and drought‐tolerant plant, four‐wing saltbush [Atriplex canescens (Pursh) Nutt.], was chosen for the trial. A series of 3 by 3 m plots were established in quadruplicate on the test site to evaluate growth of four‐wing saltbush transplants alone or with compost addition. Results show that >80% of the transplanted saltbush survived after 1.5 yr in both treatments. Enumeration of heterotrophs and community structure analysis were conducted to monitor bacterial community changes during plant establishment as an indicator of plant and soil health. The bacterial community was evaluated using denaturing gradient gel electrophoresis (DGGE) analysis of 16S rDNA PCR gene products from tailings samples taken beneath transplant canopies. Significant differences in heterotrophic counts and community composition were observed between the two treatments and unplanted controls throughout the trial, but treatment effects were not observed. The results suggest that compost is not necessary for plant establishment at this site and that plants, rather than added compost, is the primary factor enhancing bacterial heterotrophic counts and affecting community composition.
Colloid Mobilization and Arsenite Transport in Soil Columns: Effect of Ionic Strength
Authors: Zhang Hua , Selim H.M.
Published: July 2007

Colloid generation and transport in soils is of significance because of suspected colloid‐facilitated transport of contaminants to the groundwater. In this study, colloid mobilization and its effect on the transport of arsenite [As(III)] were investigated in Olivier (fine‐silty, mixed, active, thermic Aquic Fraglossudalfs) and Windsor (mixed, mesic typic Udipsamments) soil columns. Input solution of 10 mg L−1As(III) in 0.01MNaCl was applied to water‐saturated columns, and followed by leaching with deionized water (DIW). Flow interruptions were performed during the As(III) input and DIW leaching phases. Turbidity, electrical conductivity (EC), and pH of column effluents were monitored with time. Total and dissolved concentrations of As, Fe, and Al were analyzed. Effluent results demonstrated that colloid‐facilitated transport contributed little to arsenic movement when the solution ionic strength was maintained constant. Mobilization of colloidal amorphous material and enhanced transport of As(III) were observed as a result of changes in ionic strength of the input solution. The peak of colloid generation coincided with peak concentrations of Fe, suggesting mobilization of Fe oxides and facilitated transport of As(III) adsorbed on oxide surfaces. Colloid mobilization was enhanced due to flow interruption in the Olivier column, which suggests slow dissociation of aggregated colloidal particles. Moreover, effluent results indicate significant effect of organic matter in stabilizing aggregates of colloidal particles.
The Contribution of Ice Cover to Sediment Resuspension in a Shallow Temperate Lake: Possible Effects of Climate Change on Internal Nutrient Loading
Authors: Niemistö Juha P. , Horppila Jukka
Published: July 2007

The effect of ice cover on sediment resuspension and internal total P (Tot‐P) loading was studied in the northern temperate Kirkkojärvi basin in Finland. The gross sedimentation and resuspension rates were estimated with sediment traps during ice‐cover and ice‐free periods. After ice break, the average gross sedimentation rate increased from 1.4 to 30.0 g dw m−2 d−1 Resuspension calculations showed clearly higher values after ice break as well. Under ice cover, resuspension ranged from 50 to 78% of the gross sedimentation while during the ice‐free period it constituted from 87 to 97% of the gross sedimentation. Consequently, the average resuspension rate increased from 1.0 g dw m−2 d−1 under ice‐cover to 27.0 g dw m−2 d−1 after thaw, indicating the strong effect of ice cover on sediment resuspension. To estimate the potential effect of climate change on internal P loading caused by resuspension we compared the Tot‐P loading calculations between the present climate and the climate with doubled atmospheric CO2 concentration relative to the present day values (ice cover reduced from current 165 to 105 d). The annual load increased from 7.4 to 9.4 g m−2 In conclusion, the annual internal Tot‐P loading caused by resuspension will increase by 28% in the Kirkkojärvi basin if the 2 × CO2 climate scenario comes true.
Diet Modification to Reduce Phosphorus Surpluses: A Mass Balance Approach
Authors: Maguire R. O. , Crouse D. A. , Hodges S. C.
Published: July 2007

Diet modification to reduce phosphorus (P) concentrations in manures has been developed in response to environmental concerns over P losses from animal agriculture to surface waters. We used USDA‐NASS statistics on animal numbers and crop production to calculate county scale mass balances for manure P production, P removed in harvested portion of crops, and the potential effects of diet modification. Although spreading manure evenly over all crop acreage within a county is unlikely to occur, these calculations give a good indication as to the impact diet modification to reduce P can have at a regional or national scale. There was a high degree of regional variability in manure P surpluses (e.g., with the large crop acreages in the grain belt leading to large P offtake in crops preventing most P surpluses). In 89% of counties, there was a deficit of manure P relative to crop P removal; therefore there was a manure P surplus in 11% of counties. Diet modification decreased the percentage of states with a manure P surplus from 11 to 8%, a decrease of approximately 27%. Diet modification decreased the percentage of counties with the greatest surpluses of manure P (>30 kg ha−1) from 3% of all counties to 1%. Diet modification to decrease manure P is an important part of strategies to alleviate environmental concerns associated with surplus manure P in many areas, but additional strategies to deal with manure P surpluses are needed in some areas.
A Stochastic Model for Colloid Transport and Deposition
Authors: Bradford S. A. , Toride N.
Published: July 2007

Profiles of retained colloids in porous media have frequently been observed to be hyper‐exponential or non‐monotonic with transport depth under unfavorable attachment conditions, whereas filtration theory predicts an exponential profile. In this work we present a stochastic model for colloid transport and deposition that allows various hypotheses for such deviations to be tested. The model is based on the conventional advective dispersion equation that accounts for first‐order kinetic deposition and release of colloids. One or two stochastic parameters can be considered in this model, including the deposition coefficient, the release coefficient, and the average pore water velocity. In the case of one stochastic parameter, the probability density function (PDF) is characterized using log‐normal, bimodal log‐normal, or a simple two species/region formulation. When two stochastic parameters are considered, then a joint log‐normal PDF is employed. Simulation results indicated that variations in the deposition coefficient and the average pore water velocity can both produce hyper‐exponential deposition profiles. Bimodal formulations for the PDF were also able to produce hyper‐exponential profiles, but with much lower variances in the deposition coefficient. The shape of the deposition profile was found to be very sensitive to the correlation of deposition and release coefficients, and to the correlation of pore water velocity and deposition coefficient. Application of the developed stochastic model to a particular set of colloid transport and deposition data indicated that chemical heterogeneity of the colloid population could not fully explain the observed behavior. Alternative interpretations were therefore proposed based on variability of the pore size and the water velocity distributions.
Pyrene Mineralization by Mycobacterium sp. Strain KMS in a Barley Rhizosphere
Authors: Child R. , Miller C. D. , Liang Y. , Sims R. C. , Anderson A. J.
Published: July 2007

To determine whether the soil Mycobacterium isolate KMS would mineralize pyrene under rhizosphere conditions, a microcosm system was established to collect radioactive carbon dioxide released from the labeled polycyclic aromatic hydrocarbon. Microcosms were designed as sealed, flow‐through systems that allowed the growth of plants. Experiments were conducted to evaluate mineralization of 14C‐labeled pyrene in a sand amended with the polycyclic aromatic hydrocarbons degrading Mycobacterium isolate KMS, barley plants, or barley plants with roots colonized by isolate KMS. Mineralization was quantified by collecting the 14CO2 produced from 14C‐labeled pyrene at intervals during the 10‐d incubation period. Roots and foliar tissues were examined for 14C incorporation. Mass balances for microcosms were determined through combustion of sand samples and collection and quantification of 14CO2 evolved from radiolabeled pyrene. No pyrene mineralization was observed in the sterile control systems. Greater release of 14CO2 was observed in the system with barley colonized by KMS than in microcosms containing just the bacterium inoculum or sterile barley plants. These findings suggest that phytostimulation of polycyclic aromatic hydrocarbons mineralization could be applied in remediation schemes.
Insurers are jockeying for bank capital, says insider
Authors: Stone Edward J.
Published: July 2007

Banks can boost profits by getting involved in the insurance industry. But they don't have to sell insurance products to do it.
After Barnett: Where do we go from here?
Authors: Stone Edward J.
Published: July 2007

The Supreme Court issued a resounding afjbnution of bank insurance powers in the Barnett case. But does this mean the end of anti‐affiliation statutes?
Overcoming the risks of selling insurance
Authors: Stone Edward J.
Published: July 2007

Life insurance is costly to sell—even for insurance companies.
Modernization bill stalls; Hawke awaits confirmation
Authors: Stone Edward J.
Published: July 2007

By October, the financial modernization bill had stalled in Congress.
H.R. 10: A battle of the bills?
Authors: Stone Edward J.
Published: July 2007

Which will win: the Senate bill or the House version?
Determination of field‐incurred pyrimethanil residues in persimmon (Diospyros kaki Linn) by liquid chromatography
Authors: Shim Jae‐Han , Abd El‐Aty A. M. , Choi Jeong‐Heui , Kang Cheol‐Ah
Published: July 2007

Field trials have been carried out to determine the residues of the fungicide pyrimethanil in persimmon (Diospyros kaki Linn) after field treatment. Three treatments using pyrimethanil (PYR 30% WP) were carried out on persimmon trees at a recommended dose rate: the former was sprayed at two different times at 30 and 21 days prior to harvesting; the second was sprayed three times at 40, 30 and 21 days prior to harvesting; and the third was sprayed four times at 40, 30, 21 and 14 days prior to harvesting. The analysis was based on liquid–liquid extraction and solid‐phase extraction followed by liquid chromatography with ultraviolet detection at 268 nm. Pyrimethanil was confirmed by high‐performance liquid chromatography–mass spectrometry HPLC‐MS in the selected ion monitoring mode. The method was validated with spiked fruit samples at concentrations of 0.1 and 0.4 ppm. Average recoveries (three replicates) ranged from 87.1 to 92.1% with relative standard deviations between 4.5 and 11.98%. The calculated limit of detection was 0.02 ppm and the limit of quantitation was 0.07 ppm. After two, three or four applications, pyrimethanil residues on persimmon averaged 0.44, 0.48 or 0.53 ppm, respectively; all of these values were below the maximum residue level established by the Korean Food and Drug Administration (5.0 ppm). This indicates that pyrimethanil residues declined to a level well below the maximum residue level within the 14 day period between the last application and harvesting. Copyright © 2007 John Wiley & Sons, Ltd.
Rhodium‐Catalyzed [2+2+1+1] Cyclocarbonylative Coupling of Alkynes with Carbon Monoxide Affording Tetrasubstituted p‐Benzoquinones
Authors: Huang Qiufeng , Hua Ruimao
Published: July 2007

In this strategy, the tetrasubstituted benzoquinones have been prepared directly by a [2+2+1+1] cyclocarbonylative coupling reaction of internal alkynes with CO in the presence of [RhCl(CO)2]2. The low concentration of CO in the reaction is the crucial point for the chemoselective formation of tetrasubstituted benzoquinones in good to high yields. Functional groups such as chloro, methoxy, cyano, vinyl, fluoro, and carboxylate are tolerated under the reaction conditions.
Age‐ and experience‐dependent expression of Dynamin I and Synaptotagmin I in cat visual system
Authors: Cnops Lieselotte , Hu Tjing‐Tjing , Vanden Broeck Jozef , Burnat Kalina , van den Bergh Gert , Arckens Lutgarde
Published: July 2007

Dynamin I (Dyn I) and Synaptotagmin I (Syt I) are essential for endocytosis‐exocytosis processes, thus for neurotransmission. Despite their related function at presynaptic terminals, Dyn I and Syt I displayed opposite expression patterns during visual cortex maturation in the cat. Dyn I was more abundantly expressed in adults, while Syt I exhibited higher levels in kittens of postnatal day 30 (P30). In area 17 this developmental difference was most obvious in layers II/III. Layer VI displayed a strong hybridization signal for both molecules, independent of age. In addition, Syt I levels were higher in posterior compared to anterior area 17 in adult subjects. Moreover, in higher‐order visual areas Syt I was unevenly distributed over the cortical layers, thereby setting clear areal boundaries in mature cortex. In contrast, Dyn I was rather homogeneously distributed over extrastriate areas at both ages. Both molecules thus demonstrated a widespread but different distribution and an opposite temporal expression pattern during visual system development. Notably, monocular deprivation during the critical period of ocular dominance plasticity significantly decreased Syt I expression levels in area 17 ipsilateral to the deprived eye, while no effect was observed on Dyn I expression. We therefore conclude that visual experience induces changes in Syt I expression that may reflect changes in constitutive exocytosis involved in postnatal structural refinements of the visual cortex. On the other hand, the spatial and temporal expression patterns of Dyn I correlate with the establishment and maintenance of the mature neuronal structure rather than neurite remodeling. J. Comp. Neurol. 504:254–264, 2007. © 2007 Wiley‐Liss, Inc.
Palladium‐Catalyzed C–N Bond Activation: The Synthesis of β‐Amino Acid Derivatives from Triethylamine and Acrylates
Authors: Zou Bo , Jiang Huan‐Feng , Wang Zhao‐Yang
Published: July 2007

In the palladium‐catalyzed reaction of acrylates, C–N bond activation and acetalization occurred under different conditions. Described herein is a highly efficient palladium‐catalyzed C–N bond activation reaction and subsequent new C–N bond formation to directly construct β‐amino acids from triethylamine and acrylate esters in isolated yields of up to 95 %.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Hydroxy Derivatives of Diamantane, Triamantane, and [121]Tetramantane: Selective Preparation of Bis‐Apical Derivatives
Authors: Fokina Natalie A. , Tkachenko Boryslav A. , Merz Anika , Serafin Michael , Dahl Jeremy E. P. , Carlson Robert M. K. , Fokin Andrey A. , Schreiner Peter R.
Published: July 2007

Functionalizations of diamantane, triamantane, and tetramantane with electrophilic reagents (Br2, nitric acid) lead to various apical and medial disubstituted products that were separated and characterized individually. The highly desirable and otherwise inaccessible thermodynamically more stable apical bis‐derivatives were obtained with high preparative yields through acid catalyzed isomerizations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Cover Picture: Exploration of meso‐Substituted Formylporphyrins and Their Grignard and Wittig Reactions (Eur. J. Org. Chem. 23/2007)
Authors: Dahms Katja , Senge Mathias O. , Bakar M. Bakri
Published: July 2007

The cover picture shows the synthesis of formylporphyrins by Umpolung reactions that use 1,3‐dithian‐2‐ylporphyrins as masked synthons. This method offers a new pathway for the preparation of free‐base and metallo formylporphyrins under mild conditions. Grignard and Wittig reactions have been performed to demonstrate the wide range of applications for formylporphyrins. Details are discussed in the article by M. O. Senge et al. on p. 3833 ff.
Determination of human blood glucose levels using microchip electrophoresis
Authors: Maeda Eiki , Kataoka Masatoshi , Hino Mami , Kajimoto Kazuaki , Kaji Noritada , Tokeshi Manabu , Kido Jun‐ichi , Shinohara Yasuo , Baba Yoshinobu
Published: July 2007

A high‐performance monitoring system for human blood glucose levels was developed using microchip electrophoresis with a plastic chip. The combination of reductive amination as glucose labeling with fluorescent 2‐aminoacridone (AMAC) and glucose‐borate complex formation realized the highly selective detection of glucose even in a complex matrix such as a blood sample. The migration time of a single peak, observed on an electropherogram of AMAC‐labeled plasma, closely resembled that of glucose standard solution. The treatment of plasma with hexokinase or glucokinase for glucose phosphorylation resulted in a peak shift from approximately 145 to 70 s, corresponding to glucose and glucose‐6‐phosphate, respectively. A double‐logarithm plot revealed a linear relationship between glucose concentration and fluorescence intensity in the range of 1–300 μM of glucose (r2 = 0.9963; p <0.01), and the detection limit was 0.92 μM. Furthermore, blood glucose concentrations estimated from the standard curves of three subjects were compared with results obtained by conventional colorimetric analysis using glucose dehydrogenase. Good correlation was observed between methods according to simple linear regression analysis (p <0.05). The reproducibility of the assay was about 6.3–9.1% (RSD) and the within‐days and between‐days reproducibility were 1.6–8.4 and 5.2–7.2%, respectively. This system enables us to determine blood glucose with high sensitivity and accuracy, and will be applicable to clinical diagnosis.
Temporal trends in the proportion cured for cancer of the colon and rectum: A population‐based study using data from the Finnish Cancer Registry
Authors: Lambert Paul C. , Dickman Paul W. , Österlund Pia , Andersson Therese , Sankila Risto , Glimelius Bengt
Published: July 2007

Colorectal cancer is the third most common cancer worldwide and the second most common cancer in Europe. Cumulative relative survival curves for both cancer of the colon and cancer of the rectum generally plateau after ∼6–8 years. When this occurs, “population” or “statistical” cure is reached. We analyzed data from the Finnish Cancer Registry over a 50‐year period using methods that simultaneously estimate the proportion of patients cured of disease (the cure fraction) and the survival time distribution of the “uncured” group. Our primary aim was to investigate temporal trends in the cure fraction and median survival of the uncured by age group for both cancer of the colon and rectum. For both cancers, the cure fraction has increased dramatically over time for all age groups. However, the difference in the cure fraction between age groups has reduced over time, particularly for cancer of the colon. Median survival in the uncured has also increased over time in all age groups but there still remains an inverse relationship between age and median survival, with shorter median survival with increasing age. The reasons for these impressive increases in patient survival are complex, but are highly likely to be strongly related to many improvements in cancer care over this same time period. © 2007 Wiley‐Liss, Inc.
Lifetime and baseline alcohol intake and risk of colon and rectal cancers in the European prospective investigation into cancer and nutrition (EPIC)
Authors: Ferrari Pietro , Jenab Mazda , Norat Teresa , Moskal Aurelie , Slimani Nadia , Olsen Anja , Tjønneland Anne , Overvad Kim , Jensen Majken K. , Boutron‐Ruault Marie‐Christine , Clavel‐Chapelon Françoise , Morois Sophie , Rohrmann Sabine , Linseisen Jakob , Boeing Heiner , Bergmann Manuela , Kontopoulou Dimitra , Trichopoulou Antonia , Kassapa Christina , Masala Giovanna , Krogh Vittorio , Vineis Paolo , Panico Salvatore , Tumino Rosario , Gils Carla H. van , Peeters Petra , Bueno‐de‐Mesquita H. Bas , Ocké Marga C. , Skeie Guri , Lund Eiliv , Agudo Antonio , Ardanaz Eva , López Dolores C. , Sanchez Maria‐Jose , Quirós José R. , Amiano Pilar , Berglund Göran , Manjer Jonas , Palmqvist Richard , Guelpen Bethany Van , Allen Naomi , Key Tim , Bingham Sheila , Mazuir Mathieu , Boffetta Paolo , Kaaks Rudolf , Riboli Elio
Published: July 2007

Alcohol consumption may be associated with risk of colorectal cancer (CRC), but the epidemiological evidence for an association with specific anatomical subsites, types of alcoholic beverages and currentvs.lifetime alcohol intake is inconsistent. Within the European Prospective Investigation into Cancer and Nutrition (EPIC), 478,732 study subjects free of cancer at enrolment between 1992 and 2000 were followed up for an average of 6.2 years, during which 1,833 CRC cases were observed. Detailed information on consumption of alcoholic beverages at baseline (all cases) and during lifetime (1,447 CRC cases, 69% of the cohort) was collected from questionnaires. Cox proportional hazard models were used to examine the alcohol‐CRC association. After adjustment for potential confounding factors, lifetime alcohol intake was significantly positively associated to CRC risk (hazard ratio, HR = 1.08, 95%CI = 1.04–1.12 for 15 g/day increase), with higher cancer risks observed in the rectum (HR = 1.12, 95%CI = 1.06–1.18) than distal colon (HR = 1.08, 95%CI = 1.01–1.16), and proximal colon (HR = 1.02, 95%CI = 0.92–1.12). Similar results were observed for baseline alcohol intake. When assessed by alcoholic beverages at baseline, the CRC risk for beer (HR = 1.38, 95%CI = 1.08–1.77 for 20–39.9vs.0.1–2.9 g/day) was higher than wine (HR = 1.21, 95%CI = 1.02–1.44), although the two risk estimates were not significantly different from each other. Higher HRs for baseline alcohol were observed for low levels of folate intake (1.13, 95%CI = 1.06–1.20 for 15 g/day increase) compared to high folate intake (1.03, 95%CI = 0.98–1.09). In this large European cohort, both lifetime and baseline alcohol consumption increase colon and rectum cancer risk, with more apparent risk increases for alcohol intakes greater than 30 g/day. © 2007 Wiley‐Liss, Inc.
Kleine Kohlenstoff‐Ringe, VIII Valenzisomerisierung von cis‐ und trans‐2‐Vinyl‐cyclopropylisocyanat
Authors: Vogel Emanuel , Erb Rolf , Lenz Günther , Bothner‐By Aksel A.
Published: July 2007

cis‐ und trans‐2‐Vinyl‐cyclopropylisocyanat wurden ausgehend von dem Addukt aus Butadien und Diazoessigester nach herkömmlichen Methoden synthetisiert. Das cis‐2‐Vinyl‐cyclopropylisocyanat konnte allerdings nicht in Substanz gefaßt werden, da es sich bereits unter seinen Bildungsbedingungen (70°) durch eine Valenzisomerisierung vom Typus der Cope‐Umlagerung, gefolgt von einer Prototropie, in das zweifach ungesättigte Siebenring‐Lactam III umwandelt. Die Isomerisierung des trans‐2‐Vinyl‐cyclopropylisocyanats, die ebenfalls III liefert, erfordert demgegenüber eine Pyrolyse bei 350°. cis‐ und trans‐2‐Vinyl‐cyclopropylisocyanat entsprechen somit in ihrem thermischen Verhalten völlig dem Isomerenpaar cis‐ und trans‐1.2‐Divinyl‐cyclopropan. Es werden weiterhin Versuche zur Überführung des Lactams III in Azepine beschrieben.
Die isomeren 3.5‐Di‐tert.‐butyl‐cyclohexanole Solvolysegeschwindigkeiten ihrer Toluolsulfonate
Authors: Hanack Michael , Heinz Karl‐Wolfgang
Published: July 2007

Die isomeren 3.5‐Di‐tert.‐butyl‐cyclohexanole A, B und C werden in reiner Form dargestellt und in ihrer Konfiguration zugeordnet. Das trans‐cis‐3.5‐Di‐tert.‐butyl‐cyclohexanol (B) liegt überwiegend in der twist‐Konformation vor. Im Vergleich zu den Tosylaten des all‐cis‐ und des trans‐trans‐Isomeren zeigt sein Tosylat bei der Äthanolyse und Acetolyse eine stark erhöhte Reaktionsgeschwindigkeit.
Synthesen und Reaktionen von Pyrazolo[1.5‐a]pyrimidinen, III
Authors: Ried Walter , Peuchert Klaus‐Peter
Published: July 2007

2‐Amino‐pyrazolo[1.5‐a]pyrimidine werden über 2‐Brom‐pyrazolo[1.5‐a]pyrimidine aus den 2‐Hydroxy‐pyrazolo[1.5‐a]pyrimidinen synthetisiert und hinsichtlich ihrer chemischen Eigenschaften untersucht.
Über das 1.5.8a.9‐Tetraaza‐fluoren‐System Die Synthese von Pyrido[3′.2′:4.3]‐pyrazolo[1.5‐a]pyrimidinen
Authors: Ried Walter , Peuchert Klaus‐Peter
Published: July 2007

2‐Amino‐pyrazolo[1.5‐a]pyrimidine kondensieren mit 1.3‐Dicarbonylverbindungen zu 1.5.8a.9‐Tetraaza‐fluorenen (Pyrido[3′.2′: 4.3]pyrazolo[1.5‐a]pyrimidinen). Durch Kondensation der 2‐Amino‐pyrazolo[1.5‐a]pyrimidine mit cyclischen 1.3‐Diketonen vom Typ des 2‐Acetyl‐cyclohexanons entstehen Pyrimido‐[2′.1′: 5.1]pyrazolo[3.4‐c]isochinoline. Die Eigenschaften der neuen, heterocyclischen Systeme werden beschrieben.
Über Formazylverbindungen, XIII Naphthalin‐bis‐formazane und Naphthalin‐bis‐tetrazoliumbromide
Authors: Ried Walter , Schendzielorz Dorothea
Published: July 2007

Es werden fünf Naphthalin‐bis‐formazane und deren Oxydationsprodukte beschrieben.
Solanum‐Alkaloide, XLVIII Abbau von Soladulcidin und Tomatidin zu den enantiomeren 5‐Methyl‐piperidonen‐(2). Zur Stereochemie der Spirosolan‐Alkaloide an C‐22 und C‐25
Authors: Schreiber Klaus
Published: July 2007

Die Spirosolan‐Alkaloide Soladulcidin (I) und Tomatidin (III) wurden über die entsprechenden N‐Monoacetyl‐ bzw. N.N‐Diacetyl‐3bT‐acetoxy‐amino‐δ20(22)‐5α‐furostene V a und b bzw. VIa und b zu 3ß‐Acetoxy‐δ16‐5α‐pregnen‐20‐on (IX) sowie (R)‐(+)‐5‐Methyl‐piperidon‐(2) (Xa) bzw. der enantiomeren (S)‐(–‐)‐Verbindung Xb abgebaut. Xa und Xb ließen sich über die enantiomeren 4‐Methyl‐5‐valerolactone XIIa und XIIb in (R)‐(–‐)‐ bzw. (S)‐(+)‐2‐Methyl‐glutarsäure (XVI a bzw. b) überführen. Die Stereochemie der Spirosolane an C‐22 wird diskutiert. Nach bisher vorliegenden Befunden haben Soladulcidin (I) und Solasodin (II) (22R : 25R)‐Konfiguration, hingegen Tomatidin (III) und Tomatidenol (IV) (22S : 25S)‐Konfiguration.
Dissoziationskonstanten von D‐Galaktosamin
Authors: Carlo Michael J. , Zimmerman jr. Howard K.
Published: July 2007

Die Protolysegleichgewichte wurden bei 15–50° für verdünnte Lösungen von Galaktosamin·HCl bestimmt. galaktosamin hat etwa 80% der Basizität des Glucosamins und ist etwa 2.5 mal basischer als Mannosamin.
Über hochacide Kohlenwasserstoffe, VI1)
Authors: Kuhn Richard , Fischer Herbert , Rewicki Dieter , Fischer Hans
Published: July 2007

Die Darstellung neuer Propene, Pentadiene und Heptatriene mit Biphenylenresten wird beschrieben. Diese Synthesen, bei denen auch von 1.2.7.8‐Dibenzo‐fluoren und von 3.4.5.6‐Dibenzo‐fluoren ausgegangen wurde, lieferten hochacide Kohlenwasserstoffe. Die tieffarbigen Anionen zeigen große Unterschiede in der Empfindlichkeit gegen Sauerstoff.
Über organische Katalysatoren, LXXVII1). Bimolekulare organische Mischkatalysatoren, IV2)
Authors: Langenbeck Wolfgang , Seltmann Guntram , Honigmann Gerhard
Published: July 2007

Es werden eine Anzahl von Zinkchelaten beschrieben, welche die Oxydation von N‐Benzyl‐dihydro‐nicotinsäureamid bei Gegenwart von 9‐Phenyl‐flavin beschleunigen. In wäßrigäthanolischer Lösung wird dabei gleichzeitig Acetaldehyd gebildet.
Spindichteverteilung in Radikalen, III1). Die Beteiligung von Phenylresten an der Aroxylmesomerie
Authors: Rieker Anton , Scheffler Klaus
Published: July 2007

Aus ESR‐Untersuchungen an 15 verschiedenartig substituierten 2.6‐Di‐tert.‐butyl‐4‐phenyl‐phenoxylen, deren Synthese beschrieben wird, muß für die 4‐Phenylgruppe eine der tert.‐Butylgruppe ähnliche Substituentenwirkung auf das Aroxylringsystem angenommen werden. Die Summe der freien Spindichtenwerte im 4‐Phenylring wird zu etwa +7% abgeschätzt. Dabei sind die Kopplungsparameter der Protonen an den C‐Atomen 3, 5, 2′, 4′ und 6′ bei ein und derselben Verbindung innerhalb der Meßgenauigkeit identisch. Verschiedenartige Substitution des 4‐Phenylringes [Br, C6H5, CH3, C(CH3)3, OCH3] ändert diese Symmetrie nur unwesentlich.
Nucleophile Substitutionen, VI. Umsetzungen von 4‐Nitro‐fluorbenzol mit sekundären Aminen
Authors: Suhr Harald
Published: July 2007

Für die Umsetzung von 19 sekundären Aminen mit 4‐Nitro‐fluorbenzol in Dimethylsulfoxyd werden die RG‐Konstanten bestimmt. Die Abhängigkeit dieser Werte sowie der Aktivierungsenergien und Aktivierungsentropien von der Struktur der Amine wird diskutiert.
Derivate des Methylendioxybenzols, XV. Schwefel und Selen enthaltende Heterocyclen des Brenzcatechin‐methylenäthers
Authors: Dallacker Franz , Kaiser Ernst , Uddrich Peter
Published: July 2007

Wir beschreiben die Darstellung von Methylendioxy‐benzologen des Thiophens, des Selenophens und des Thiazols sowie die Synthese des 2.3.6.7‐Bis‐methylendioxy‐dibenzothiophens und des 2.3.6.7‐Bis‐methylendioxy‐thioxanthons. Ferner werden Synthesen von Heterocyclen mit zwei Schwefelatomen und von 6.7‐Methylendioxy‐ und 6.7‐Äthylendioxy‐2H‐1.2.4‐benzothiadiazin‐1.1‐dioxyden mitgeteilt.
Grignard‐ und Friedel‐Crafts‐Reaktionen mit ungesättigten 2H‐Oxazolonen‐(5)
Authors: Mustafa Ahmed , Sammour Abd Elmaged , Eldeen Mohamed Motaweh Nour , Salama Tayseer , Hilmy Mustafa Kamal
Published: July 2007

2‐Benzyliden‐4‐phenyl‐2H‐oxazolon‐(5) (1d) reagiert mit Phenylmagnesiumbromid zum Oxazolon 3. Mit Methyl‐ und Benzylmagnesiumhalogeniden erhält man aus 1d die Amide 5a—b. Alkalische Hydrolyse von 3 liefert die Säure 4, deren Struktur durch unabhängige Synthese bewiesen wurde. Die Reaktion von 1d mit Benzol unter Friedel‐Crafts‐Bedingungen führt zur Säure 6, die ebenfalls unabhängig synthetisiert wurde. Mit 2 Moll. Toluol oder Xylol reagiert 1d unter Bildung des Amids 8. Die NMR‐ und IR‐Spektren der Reaktionsprodukte werden diskutiert. Aromatische Thiole werden an die C=N‐Bindung von 1b und 1d addiert und liefern dabei die Arylmercapto‐oxazolone 11a—b.
Ein neues Pteridin aus Mycobacterium smegmatis
Authors: Goto Miki , Kobayashi Kiyotaka , Sato Hiroshi , Korte Friedhelm
Published: July 2007

Aus Mycobacterium smegmatis wird ein neues Pterin 2 mit der Summenformel C17H23N5O12 isoliert. Die Permanganatoxydation liefert 2‐Amino‐4‐hydroxy‐pteridin‐carbonsäure‐(6). Durch Hydrolyse mit Säuren oder ß‐Glucuronidase wird 2 in Glucuronsäure und das Aglykon 3 gespalten. Perjodatabbau von 3 ergibt 2‐Amino‐4‐hydroxy‐pteridin‐aldehyd‐(6). — Aus diesen Befunden und dem Massenspektrum von 2 wird für das neue Pterin die Struktur eines 2‐Amino‐4‐hydroxy‐6‐[1′.2′.3′.4′.5′‐pentahydroxy‐pentyl]‐pteridin‐2′‐ß‐glucuronids abgeleitet.
Die intramolekulare Wechselwirkung zwischen Heterocyclen in Coenzymen, II1). α‐Nicotinamid‐adenin‐dinucleotid
Authors: Pfleiderer Gerhard , Woenckhaus Christoph , Nelböck‐Hochstetter Michael
Published: July 2007

Die Abtrennung von α‐Nicotinamid‐adenin‐dinucleotid (α‐NAD)

Es werden folgende Abkiirzungen verwendet : Nicotinamid‐adenin‐dinucleotid = NAD, Dihydronicotinamid‐adenin‐dinucleotid = NADH, Nicotinamid‐mononucleotid = NMN.

) aus natürlichem NAD gelingt durch Säulenchromatographie an Dowex‐1‐formiat mit Ameisensäure. Das zwischen Nicotinamid und Ribose α‐glykosidisch gebundene α‐NAD zeigt ähnlich dem allein enzymatisch wirksamen β‐NAD eine Wechselwirkung zwischen Pyridin‐ und Purin‐Ring: Nach der Spaltung mit Schlangengift‐pyrophosphatase tritt bei 260 mμ ein Extinktionsanstieg ein. Durch UV‐Licht (λ = 260 mμ) wird die Fluoreszenz des längerwellig absorbierenden α‐Dihydronicotinamid‐Ringes angeregt. α‐NAD und α‐Nicotinamid‐mononucleotid (NMN) unterscheiden sich optisch nur wenig von den β‐Isomeren, chemisch durch erschwerte Hydrolyse der α‐glykosidisch gebundenen Ribose. Das hydrierte α‐isomere Coenzym ist sehr unbeständig. Es erweist sich als starker Hemmstoff in verschiedenen Dehydrogenase‐Systemen.
Aminosäuren und Peptide, XIII. Darstellung aktiver Pyridyl‐(3)‐ester N‐geschützter Aminosäuren und Peptide sowie deren Anwendung zur Peptid‐Synthese
Authors: Taschner Emil , Rzeszotarska Barbara , Lubiewska Lucja
Published: July 2007

Pyridyl‐(3)‐ester N‐geschützter Aminosäuren bzw. Peptide (Tab. 1) werden mittels 3‐Hydroxypyridins bevorzugt nach der Dicyclohexylcarbodiimid‐Methode dargestellt und mit Aminosäureestern in die entsprechenden N‐geschützten Peptidester (Tab. 2) verwandelt.
Untersuchungen über die Plastein‐Reaktion, VIII1). Spezifität des Pepsins bei der Kondensationsreaktion
Authors: Determann Helmut , Heuer Jutta , Jaworek Dieter
Published: July 2007

Es wird die Synthese der neuen Pentapeptide L‐Tyrosyl‐L‐leucyl‐glycyl‐L‐glutamyl‐L‐leucin (1), L‐Tyrosyl‐L‐leucyl‐glycyl‐L‐glutamyl‐L‐isoleucin (2), L‐Tyrosyl‐L‐leucyl‐glycyl‐L‐glutamyl‐L‐valin (3), D‐Phenylalanyl‐L‐leucyl‐glycyl‐L‐glutamyl‐L‐phenylalanin (4) und L‐Tyrosyl‐L‐leucyl‐glycyl‐L‐glutamyl‐D‐phenylalanin (5) beschrieben. Anhand dieser Substrate und früherer Ergebnisse haben wir festgestellt, daß Pepsin als Katalysator bei der Kondensationsreaktion und bei der Protein‐Hydrolyse die gleiche Spezifität besitzt. Während sich das Peptid 1 (mit Leucin am Carboxyl‐Ende) leicht kondensieren läßt, sind 2 (mit Isoleucin) und 3 (mit Valin am Carboxyl‐Ende) keine geeigneten Substrate für die Plastein‐Reaktion. D‐Aminosäuren an beiden Enden (4, 5) verhindern die enzymatische Kondensation.
Über Tosylperchlorat1)
Authors: Klages Friedrich , Malecki Friedrich E.
Published: July 2007

Tosylperchlorat ist in Nitromethan bei –20° beständig. Es dissoziiert in flüssigem Schwefel‐dioxid weitgehend in die freien Ionen und vermag als stärkstes der bisher bekannten Sulfonylierungsmittel aromatische Verbindungen zu Sulfonen und Trialkylamine zu N.N.N‐Trialkyl‐sulfonamidiumsalzen zu tosylieren. Die bei 0° eintretende langsame Zersetzung beruht auf einer Oxydation des Nitromethans durch das Perchlorat‐Ion.
Spaltung von p‐Toluolsulfony‐hydrazonen mit Natriumamid und Natriumhydrid
Authors: Kirmse Wolfgang , Bülow Bernd‐G. , Schepp Horst
Published: July 2007

Die Umsetzung von Tosylhydrazonen aliphatischer Ketone mit Natriumamid oder Natriumhydrid verläuft ohne Umlagerung und führt vorwiegend zu 1‐Olefinen. Aus α,β‐ungesättigten Tosylhydrazonen entstehen Diene. Die Reaktion unterscheidet sich in Ergebnis und Mechanismus stark von der bekannten Spaltung der Tosylhydrazone mit Natriummethylat. Versuche mit deuterierten Tosylhydrazonen weisen auf eine 1.4‐Eliminierung der Sulfinsäure hin [Gl. (3)].
Reaktionen mit Diazocarbonylverbindungen, XXII1). Über die Reaktion von Anilen mit Tosylhydrazid
Authors: Ried Walter , Ritz Michael
Published: July 2007

Im Gegensatz zum Anthrachinon setzt sich das aus Anthron und Nitrosobenzol erhältliche Anthrachinonanil glatt mit Tosylhydrazid um. Das intermediär durch Austausch des Anilrestes gebildete Monotosylhydrazon zerfällt in Anthrachinon‐diazid (1) und Sulfinsäure. Allgemein lassen sich Anile über die Tosylhydrazone in Diazoverbindungen umwandeln.
Auf das Zentralnervensystem wirkende Substanzen. Synthese und Pharmakologie von N‐Aminoacetyl‐ und N‐Aminoäthyl‐1.2‐diphenyl‐äthylaminen
Authors: Zaheer Syed Husain , Sattur Pralhad Balvantrao , Rao Paturu Pramila
Published: July 2007

Eine Anzahl von N‐Aminoacetyl‐1.2‐diphenyl‐äthylaminen und der entsprechenden N‐Amino‐äthyl‐1.2‐diphenyl‐äthylamine wurde dargestellt. Ergebnisse der pharmakologischen Vorprüfung werden mitgeteilt und Struktur‐Aktivität‐Beziehungen kurz diskutiert.
Derivate des Methylendioxybenzols, XVIII. Synthese von Xanthevodin, Melicopidin und Melicopin
Authors: Dallacker Franz , Adolphen Gerd
Published: July 2007

Es wird die Darstellung der Pflanzeninhaltsstoffe Xanthevodin, Melicopidin und Melicopin, ausgehend von 2.5‐Dimethoxy‐3.4‐methylendioxy‐ bzw. 2.3‐Dimethoxy‐4.5‐methylendioxy‐jodbenzol, beschrieben.
Reaktionen mit Nitrosouracilderivaten, I. Eine neue Xanthin‐Synthese
Authors: Goldner Herbert , Dietz Günther , Carstens Ernst
Published: July 2007

Eine neuartige Xanthin‐Synthese wird beschrieben. Ausgangsstoffe sind an der 4‐Amino‐gruppe monosubstituierte 5‐Nitroso‐uracilderivate (3). Diese spalten beim Erhitzen intramolekular Wasser ab unter Bildung der Xanthine 4. Durch Oxydationsmittel entstehen aus den Nitrosouracilderivaten 3 zunächst Azomethine 12, die sich zu 7‐Hydroxy‐xanthinen 13 cyclisieren.
Aminozuckersynthesen, XVII1). D‐Rhamnosamin und 2.6‐Diamino‐2.6‐didesoxy‐D‐mannose aus N‐Acetyl‐D‐mannosamin
Authors: Gross Paul H. , Brendel Klaus , Zimmerman Howard K.
Published: July 2007

Die Glykosidierung von N‐Acetyl‐D‐mannosamin mit Äthanol durch azeotrope Destillation mit Kationenaustauscher liefert ein Gemisch der Glykoside, in dem das α‐Pyranosid überwiegt. Kristalline Derivate erhält man nach Tritylierung oder Tosylierung in 6‐Stellung. Synthesen des D‐Rhamnosamins und der 2.6‐Diamino‐2.6‐didesoxy‐D‐mannose über die 6‐Jod‐ bzw. die 6‐Azid‐Verbindung werden beschrieben.
Organozinnverbindungen, XIII. Eine Synthese von organischen Tri‐ und Tetrastannanen
Authors: Sommer Richard , Schneider Bernd , Neumann Wilhelm P.
Published: July 2007

Stannyl‐diäthyl‐amine R′3Sn—N(C2H5)2 kondensieren sich in exothermer Reaktion mit Organozinn‐dihydriden zu einheitlichen Tristannanen, mit Tetraalkyl‐dizinn‐1.2‐dihydriden zu einheitlichen linearen Tetrastannanen. Die Stannylamine können durch Stannoxane R′3Sn—OSnR′3 oder Stannyl‐methylate R′3Sn—OCH3 ersetzt werden, jedoch tritt dann nebenher oder hauptsächlich Substituentenaustausch ein. Der Reaktionsmechanismus wird untersucht.
Spirocyclische Verbindungen, VI. Spiro{bicyclo[3.3.1]nonan‐3.1′‐cyclobutan}‐ und Dispiro{bicyclo‐[3.3.1]nonan‐3.1′‐cyclobutan‐3′.1″‐cyclobutan}‐Derivate
Authors: Buchta Emil , Billenstein Siegfried
Published: July 2007

Die Spiroverbindungen 2a—e und 3a—c werden aus Bicyclo[3.3.1]nonan‐dicarbonsäure‐(3.3)‐diäthylester (1a) dargestellt.
Isonitrile, XXI. Asymmetrisch induzierte Synthesen von α‐Aminosäure‐Derivaten
Authors: Herlinger Heinz , Kleimann Helmut , Offermann Klaus , Rücker Dietrich , Ugi Ivar
Published: July 2007

(R)‐ bzw. (S)‐α‐Phenyläthylamin (4) und Isobutyraldehyd (1a) wie auch deren Schiff‐Base, das (R)‐ bzw. (S)‐Isobutyraldehyd‐α‐phenyläthylimin, reagieren mit Benzoesäure und tert.‐Butyl‐isocyanid (3) unter Vierkomponenten‐Kondensation zu einem Gemisch der Valin‐Derivate 5a—8a. In verdünnter methanolischer Lösung verläuft die Umsetzung unter überwiegender Bildung von 6a und 8a, während in konzentrierter methanolischer und äthanolischer Lösung 5a und 8a als Hauptprodukte entstehen. Analog werden aus (R)‐ bzw. (S)‐α‐Phenyläthylamin, (S)‐2‐Methyl‐butanal [(1b)‐(S)], Benzoesäure und tert.‐Butyl‐isocyanid die Isoleucin‐ und Alloisoleucin‐Derivate 5b—8b erhalten.
1‐Methyl‐Δ1.3.5(10)‐östratriendiol‐(4.17β) und 1‐Methyl‐Δ1.3.5(10)‐östratriendiol‐(2.17β)
Authors: Dannenberg Heinz , Gross Hans Joachim
Published: July 2007

Nitrierung von 1‐Methyl‐Δ1.3.5(10)‐östratrienol‐(17β)‐acetat (1) führt zu einem Gemisch der 2‐Nitro‐ und 4‐Nitro‐Verbindung (2, 3); die entsprechenden Amine (4 bzw. 5) lassen sich durch Diazotieren, Verkochen und Verseifen in 1‐Methyl‐Δ1.3.5(10)‐östratriendiol‐(2.17β) (8) und ‐diol‐(4.17β) (9) überführen, deren östrogene Wirksamkeit untersucht wird. — Versuche, 1‐Methyl‐4‐hydroxy‐Δ1.3.5(10)‐trien‐steroide aus Δ1.4‐Dienon‐(3)‐Verbindungen mit einer Sauerstoff‐Funktion an C‐4 durch Reduktion und Dienol‐Benzol‐Umlagerung oder aus Δ2‐Enon‐(4)‐steroiden über das Oxim durch Semmler‐Wolff‐Aromatisierung darzustellen, verliefen negativ.
Photosensibilisierte Carbocycloadditionen von Philodienen an Konjugene zu Cyclobutan‐Derivaten und exo‐Diels‐Alder‐Addukten
Authors: Schenck Günther Otto , Kuhls Jürgen , Krauch Carl Heinrich
Published: July 2007

Maleinsäureanhydrid und Dimethylmaleinsäureanhydrid lassen sich sowohl bei direkter photochemischer Anregung als auch, unter Vervielfachung des Umsatzes, durch Benzophenon photosensibilisiert mit cyclischen 1.3‐Dienen, Cycloheptatrien und Cyclooctatetraen zu 1 : 1‐Addukten umsetzen. Dabei treten in vielen Fällen C4‐ und C6‐Cocyclodimere nebeneinander auf. Anders als die thermische Diensynthese führt die photosensibilisierte C6‐Cocyclo‐addition zu Addukten vom exo‐Diels‐Alder‐Typ. Neben den Cocycloaddukten entstehen durch Photosensibilisation auch die C4‐ und C6‐Homocycloaddukte der Konjugene. Cycloheptatrien liefert ein kristallines und vier flüssige Homocyclodimere. – Die photosensibilisierte Copolymerisation von Maleinsäureanhydrid mit Cyclohexen ben 20° tritt bei –80° stark zurück, so daß alle stereoisomeren C4‐Cycloaddukte präparativ zugänglich werden.
Eine einfache Synthese von Carbonsäurebromiden
Authors: Bestmann Hans‐Jürgen , Mott Ludwig
Published: July 2007

Carbonsäurebromide (Tab. 1) werden aus Carbonsäuren oder deren Anhydriden mittels Triphenylphosphin‐dibromids dargestellt.
Zur chemischen Klassifizierung von Pflanzen, XXIX (Haschisch, VIII. Synthese von DL‐Cannabidiol und seinem Methylhomologen
Authors: Korte Friedhelm , Dlugosch Ernst , Claussen Uwe
Published: July 2007

Die Synthese von DL‐Cannabidiol (5a) gelingt, ausgehend von 1‐[2.6‐Dimethoxy‐4‐pentyl]‐phenyl‐3‐methyl‐butadien (2a), wobei der Terpen‐Ring durch Diels‐Alder‐Reaktion mit Methyl‐vinyl‐keton und nachfolgende Wittig‐Olefinierung aufgebaut wird. Nach der Spaltung der Methyläther erhält man die freien Cannabidiole als cis/trans‐Isomerengemisch. Es wird durch Gegenstromverteilung getrennt. Die Synthese des Methylhomologen 5b erfolgt analog.
Flavonoide, XIV. Flavonoide und Thiaflavonoide mit N‐haltigen Gruppen am Heteroring
Authors: Bognár Rezsö , Rákosi Miklós
Published: July 2007

Kontrollierte katalytische Hydrierung von 3‐Isonitroso‐flavanon (2) führt zum 3‐Amino‐flavanon (7). Dieses liefert bei der Weiterhydrierung oder mittels NaBH4 3‐Amino‐4‐hydroxy‐flavan (10) und gibt bei Säurehydrolyse ein Dihydroflavonol‐Racemat (9). Aus dem N‐Acetyl‐Derivat von 7 läßt sich 3‐Acetamino‐flavanonoxim (11) darstellen. Das aus 2 mit SnCl2/HCl erhältliche 3‐Amino‐flavon (3) wird durch Säure zu Flavonol‐(3) (4) hydrolysiert. — 1‐Thia‐flavanonoxim (13) geht bei katalytischer Hydrierung oder durch Reduktion mit LiAlH4 in 4‐Amino‐1‐thia‐flavan (14) über. Das Tosylat von 13 wird durch Neber‐Reaktion in 3‐Amino‐1‐thia‐flavanon (16) umgelagert. Derivate und Eigenschaften der genannten Verbindungen werden beschrieben.
Organozinnverbindungen, XIV. Aliphatisch substituierte Cyclostannane
Authors: Neumann Wilhelm P. , Pedain Josef , Sommer Richard
Published: July 2007

Kristalline, aliphatisch substituierte Cyclostannane entstehen in hohen Ausbeuten sowohl aus Organozinn‐dihydriden durch katalytische Wasserstoffabspaltung als auch aus Organozinn‐dihydriden mit Dialkylstannylen‐diaminen R2Sn[N(C2H5)2]2. Während so vom Diäthyl‐ und Dibutyl‐Derivat auf mehreren Wegen Cyclohexastannane 1 erhalten werden, liefert das Dicyclohexyl‐Derivat den Fünfring 4, das Di‐tert.‐butyl‐Derivat den Vierring 3 und das Diisobutyl‐Derivat auf drei unabhängigen Wegen den Neunring 2. Auf andere Weise wurde Dodecaisobutyl‐cyclohexastannan (1c) dargestellt.
Über die Oxydationsprodukte von Thiocarbonsäureamiden, XI. Infrarotspektroskopische Untersuchungen am Thioacetamid‐S‐oxid
Authors: Walter Wolfgang , Kubersky Hans Peter
Published: July 2007

Durch systematischen Austausch der C‐, H‐ und N‐Atome im Thioacetamid‐S‐oxid durch 13C, D und 15N wurde eine vollständige Zuordnung der IR‐Banden dieser Verbindung im Bereich von 3500 bis 400 cm−1 möglich.