bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lewis Acid‐Catalysed Anomerisation and Rearrangement of Alkyl D‐Glycopyranosides During Acetalisation with Methyl Pyruvate: How to Utilise it for the Preparation of 1‐(Carboxyethylidene)glycopyranosyl Donors
Authors: Ziegler Thomas , Eckhardt Elisabeth , Herold Gerhard 
Published: July 2007

AbstractThe preparation of 4,6‐O‐(1‐methoxycarbonylethylidene)‐D‐glycopyranosides 5 starting from 2,3‐di‐O‐benzoyl‐D‐glycopyranosides 1 and their 4,6‐bis‐O‐trimethylsilyl ethers 2 using methyl 2,2‐bis(phenylthio)propionate (4) and methyl pyruvate (3), respectively, under Lewis acid catalysis conditions is described. In the D‐gluco series anomerisation of alkyl β‐D‐glucopyranosides is observed as a side reaction, giving complex mixtures and low yields of the title compounds whereas alkyl‐α‐D‐glucopyranosides and alkyl or phenyl 1‐thio‐β‐D‐glucopyranosides react without anomerisation. The reactions are accompanied by isomerisation of the initially formed diastereomer (R)‐5 having an equatorial methoxycarbonyl group to the thermodynamically favoured diastereomer (S)‐5 having the methoxycarbonyl group in an axial position. In the D‐galacto series similar side reactions are observed accompanied by rearrangement to furanosides 9 of alkyl and phenyl β‐D‐galactopyranosides. The results are used for efficient syntheses of two protected disaccharides 8 and 11 representing structural fragments of the polysaccharide repeating units of Mycobacteria and Rhizobia via pyruvate acetal‐containing glucosyl and galactosyl donors 7 and 10.
Enzymatic Synthesis of ß‐L‐Fucose‐1‐phosphate and GDP‐fucose
Authors: Stiller Regine , Thiem Joachim 
Published: July 2007

AbstractFucose is an important component of complex heterooligosaccharides. Here we describe the preparative enzymatic synthesis of ß‐L‐fucose‐1‐phosphate as well as its enzymatic conversion into GDP‐fucose. Fucose (1) was converted into ß‐L‐fucose‐1‐phosphate (2) with fucose kinase (EC 2.7.1.52) obtained from porcine submaxillary glands by consumption of ATP. Syntheses carried out with the enzymes enclosed in a dialysis bag gave 19% yield of ß‐L‐fucose‐1‐phosphate. Application of the enzymes in a batch procedure using an ultrafiltration cell gave 40% yield of the fucose‐1‐phosphate. The yield could be increased to 80% if the inhibitor ADP was removed by cofactor regeneration with phosphoenolpyruvate. ß‐L‐Fucose‐1‐phosphate was isolated as various salts and analyzed by NMR spectroscopy. In a second enzymatic reaction ß‐L‐fucose‐1‐phosphate was converted into GDP‐fucose (3) by the action of GDP‐fucose pyrophosphorylase (EC 2.7.7.30) obtained from porcine submaxillary glands. In a 50‐μmolar scale reaction, yields around 20% were obtained.
Concave Reagents, 11. Concave Benzoates, Sterically Extremely Shielded Esters
Authors: Lüning Ulrich , Wangnick Carsten 
Published: July 2007

AbstractThe synthesis and the properties of concave methyl benzoates 4 are described. The difficulties encountered in their saponification and 1H‐NMR data show that these esters 4 are severely shielded. Saponification is possible via nucleophilic substitution at the methyl groups by lithium iodide in pyridines. The products are the new concave benzoic acids 5d and 5e.
Preparative Bioorganic Chemistry, XVI. Synthesis of 3,4′‐Dihydroxypropiophenone 3‐ß‐D‐Glucopyranoside, a Constituent of Betula platyphylla var. japonica, by Enzymatic Transglucosylation
Authors: Mori Kenji , Qian Zhao‐Hui , Watanabe Sadamoto 
Published: July 2007

Abstract3,4′‐Dihydroxypropiophenone 3‐ß‐D‐glucopyranoside (1a) has been synthesized, without having recourse to any protective group technology, by transglucosylation catalyzed by lactase from Kluyveromyces lactis.
Asymmetric Synthesis via Heterocyclic Intermediates, XLVIII. Asymmetric Synthesis of Diastereomerically and Enantiomerically Pure, 3‐Substituted (2S,3R)‐N‐Methylserine Esters
Authors: Beulshausen Tessa , Groth Ulrich , Schöllkopf Ulrich 
Published: July 2007

AbstractA novel method for the synthesis of N‐methylserines has been developed. The oxazolidines 4 are formed by condensation of the serine methyl esters 1 with formaldehyde. These intermediates are subsequently reduced to the N‐methylserine methyl esters 9 by an acid‐catalyzed ring opening via their iminium ions 2 with triethylsilane/trifluoroacetic acid.
Synthesis of Some Deoxymannosyl Phosphates
Authors: Niggemann Jutta , Thiem Joachim 
Published: July 2007

Abstract3‐Deoxy‐α‐D‐arabino‐hexopyranosyl‐, 4‐deoxy‐α‐D‐lyxo‐hexopyranosyl‐ and 6‐deoxy‐α‐D‐mannopyranosyl phosphates 6, 12 and 21 were synthesized by phosphorylation of the deoxygenated glycosyl chlorides 3, 9 and 18 with silver dibenzyl phosphate and subsequent deprotection of the obtained α‐dibenzyl phosphates 4, 10 and 19.
Total Synthesis of (+)‐Myomontanone and (+)‐10,11‐Didehydromyomontanone
Authors: Roussis Vassilios , Hubert Terrance D. 
Published: July 2007

AbstractThe sesquiterpenoid (+)‐myomontanone (2), a toxic component of the Australian plant Myoporum montanum, has been synthesized through a short efficient sequence. An electrochemical oxyselenation‐deselenation sequence allows oxidation of an intermediate olefin, in the presence of the furan ring, ultimatively providing the requisite enone of the natural product. This approach also allowed synthesis of (+)‐10,11‐didehydromyomontanone (13) and several other natural products of this family of furanosesquiterpenoids.
Präparative Enantiomerentrennung einer Chroman‐2‐carbonsäure durch Chromatographie von Glucose‐Derivaten
Authors: Netscher Thomas , Gautschi Iwan 
Published: July 2007

Preparative Separation of the Enantiomers of a Chroman‐2‐carboxylic Acid via Chromatography of Glucose DerivativesStarting from the commercially available racemic carboxylic acid 2a, b (S)‐Trolox methyl ether (1a), useful as a chiral reagent for capillary gas chromatography and supercritical fluid chromatography, was obtained in enantiomerically pure form (e.e. >99.9%) by the separation of esters derived from diacetone D‐glucose and subsequent saponification.
Some Reductive Transformations in the Furazano[3,4‐d]pyridazine System. — Formation of 1,2‐Dipyridazinyldiazene Derivatives
Authors: Lange Jerzy , Karolak‐Wojciechowska Janina , Tondys Hanna 
Published: July 2007

AbstractHydrogenation of 4,7‐diarylfurazano[3,4‐d]pyridazine 1‐oxides 1 on palladized carbon or platinum oxide yielded 4,5‐diamino‐3,6‐diarylpyridazines 2 and trans‐1,2‐bis(5‐amino‐3,6‐diaryl‐pyridazin‐4‐yl)diazene 1‐oxides 3, readily converted by stannous chloride into trans‐1,2‐bis(5‐amino‐3,6‐diarylpyridazin‐4‐yl)diazenes 6. Reduction of 1 with sodium tetrahydroborate gave 4,7‐diarylfurazano[3,4‐d]pyridazines 5 and 4,7‐diaryl‐4,5‐dihydrofurazano[3,4‐d]pyridazine 1‐oxides 4. The crystal structures of 3a and 4a were solved by X‐ray analysis.
Biosynthese von Naturstoffen mit einer PC‐Bindung, IX. Synthese und Einbau von (S)‐ und (R)‐2‐Hydroxy‐[2‐2H1]ethylphosphonsäure in Fosfomycin durch Streptomyces fradiae
Authors: Hammerschmidt Friedrich 
Published: July 2007

Biosynthesis of Natural Products with a P—C Bond, IX.— Synthesis and Incorporation of (S)‐ and (R)‐2‐Hydroxy‐[2‐2H1]ethylphosphonic Acid into Fosfomycin by Streptomyces fradiae(S)‐ and (R)‐2‐(benzyloxy)‐[1‐2H1]ethanol (8) were transformed into (S)‐ and (R)‐2‐hydroxy‐[2‐2H1]ethylphosphonic acid (13). These were fed to cultures of Streptomyces fradiae. The fosfomycin produced was isolated as aminopropylphosphonic acid and contained 32% Deuterium, when (S)‐13 was added to the growth medium, and no deuterium, when the antipode (R)‐13 was added as substrate. The dehydrogenase‐accepting 2‐ hydroxyethylphosphonic acid is stereospecifically removing its pro‐R hydrogen from C‐2.
Amination of 3,5‐Dinitropyridines with Liquid Ammonia/Potassium Permanganate
Authors: Woźniak Marian , Bańskira Andrzej , Szpakiewicz Barbara 
Published: July 2007

Abstract3,5‐Dinitropyridine and some of its derivatives are aminated with a liquid ammonia solution of potassium permanganate to the corresponding 2‐, 4‐ and 6‐ mono‐ and (or) di‐ and (or) triamino‐substituted compounds. The intermediate amino σ‐adducts of 3,5‐dinitropyridines are detected by 1H‐NMR spectroscopy. Quantum‐mechanical calculations for a few 3,5‐dinitropyridines suggest that the experimentally observed regioselectivity of the amination is a charge‐controlled process.
Zur Regioselektivität SH‐haltiger Nucleophile gegenüber Androsta‐1,4‐dien‐3,17‐dion, einem Vorläufer für biologisch aktive Steroide
Authors: Müller Anreas , Weiß Dieter , Beckert Rainer 
Published: July 2007

On the Regioselectivity of SH‐Containing Nucleophiles towards Androsta‐1,4‐diene‐3,17‐dione, a Precursor for Biologically Active SteroidsThioketals have been prepared from androsta‐1,4‐diene‐3,17‐dione (1) and SH‐containing compounds in the presence of different catalysts. The thioketals 4 are obtained by using the aromatic thiols 3d, 3e, and 3g, whereas the aliphatic thiols 3a and 3c yield a mixture of regioisomeric products 4–6. A higher selectivity with regard to the 17‐oxo group was observed by using the thiol 3b leading to 5b. With the araliphatic thiol 3f compound 5f is selectively formed. In contrast to the described thioketal formation, the thiol 3d yields in addition to 4d a double Michael addition product 7, which was predominantly obtained by using other catalysts and/or a higher reaction temperature.
Structure Elucidation of the Gallium–Ornibactin Complex by 2D‐NMR Spectroscopy
Authors: Stephan Holger , Freund Stefan , Meyer Jean‐Marie , Winkelmann Günther , Jung Günther 
Published: July 2007

AbstractFrom a Pseudomonas strain novel hydroxamate/carboxylate siderophores were isolated which were named ornibactins representing the modified tetrapeptide L‐Orn1(Nδ‐OH,Nδ‐acyl)‐D‐threo‐Asp(β‐OH)‐L‐Ser‐L‐Orn4(Nδ‐OH,N δ‐formyl)‐1,4‐diaminobutane. The side‐chain amino function of Orn1(Nδ‐OH,Nδ‐acyl) is acylated by 3‐hydroxyoctanoic acid in the most lipophilic component of the microheterogeneous siderophore mixture. The structure elucidation was based on GC amino acid analysis, GC‐MS and electrospray mass spectrometry of the iron complex. The 3‐hydroxyoctanoic acid and the primary sequence were established on the basis of 1H and inverse detected 13C two‐dimensional NMR spectra (COSY, TOCSY, NOESY, HMQC, HMBC) of the gallium‐ornibactin‐F complex which allowed the complete assignment of all 1H and 13C signals.
Biologically Active Glycosides from Asteroidea, XXX. – Synthesis of an Optically Active Ceramide of GM1‐Type Ganglioside from (+)‐diethyl L‐Tartrate
Authors: Metz Katrin , Honda Masanori , Komori Tetsuya 
Published: July 2007

AbstractA short total synthesis of the ceramide (2S,3R,4E)‐2‐(octadecanoylamino)‐4‐octadecene‐1,3‐diol (1) is reported, using (+)‐diethyl L‐tartrate (2) as the optically active starting material.
Studies on Heterocyclic Enaminonitriles, XIII. Reactions of Ethyl N‐2‐(3‐Cyano‐4,5‐dihydro‐2‐furyl)carbamates with Sodium Iodide
Authors: Maruoka Hiroshi , Yamagata Kenji , Yamazaki Motoyoshi 
Published: July 2007

AbstractThe reaction of ethyl N‐2‐(3‐cyano‐4,5‐dihydro‐2‐furyl)carbamate (1), 1‐cyano‐N‐(ethoxycarbonyl)cyclopropanecarboxamide (2), and ethyl 3‐cyano‐2‐oxo‐1‐pyrrolidinecarboxylate (3) with sodium iodide gave 3‐ethyl‐2‐oxo‐3‐pyrrolidinecarbonitrile (5). Similarly, the reaction of ethyl N‐2‐[3‐cyano‐4,5‐dihydro‐4‐(or ‐5‐)phenyl‐2‐furyl]carbamate (7 or 8) and trans‐1‐cyano‐N‐(ethoxycarbonyl)‐2‐phenylcyclopropane‐carboxamide (9) afforded 3‐ethyl‐2‐oxo‐5‐phenyl‐3‐pyrrolidinecarbonitrile (10).
Pheromone Synthesis, CLII. Synthesis of Blattellastanosides A and B, Chlorinated Steroid Glucosides Isolated as the Aggregation Pheromone of the German Cockroach, Blattella germanica L.
Authors: Mori Kenji , Fukamatsu Kunio , Kido Masaru 
Published: July 2007

Abstractβ‐Sitosterol (3) was converted to blattellastanosides A (1, 6α‐chloro‐4β,5‐epoxy‐5β‐stigmastan‐3β‐yl β‐D‐glucopyranoside) and B (2, 6α‐chloro‐5‐hydroxy‐5β‐stigmastan‐3β‐yl β‐D‐glucopyranoside), the arrestant components of the aggregation pheromone of the German cockroach, Blattella germanica L.
Synthese von 1,3,5‐Triamino‐2,4,6‐triphenylbenzol und dessen Reaktion mit Pikrylhalogeniden
Authors: Zierer Dirk , Dulog Lothar 
Published: July 2007

Synthesis of 1,3,5‐Triamino‐2,4,6‐triphenylbenzene and Its Reaction with Picryl Halides′,4′,6′‐Trinitro‐5′‐phenyl‐1,1′:3′,1″‐terphenyl (5) was synthesized by Ullmann reaction of 1,3,5‐trichloro‐2,4,6‐trinitrobenzene (3) with iodobenzene and copper powder in the presence of N,N‐dimethylformamide. Reduction of 5 with tin/tin(II) chloride in a mixture of hydrochloric and acetic acid yields 2′,4′,6′‐triamino‐5′‐phenyl‐1,1′:3′,1″‐terphenyl (6). By reaction of this symmetric benzenetriamine with picryl chloride and fluoride in different media, but utmost two of the three amino groups were converted into picrylamide groups to 7 and 8.
Antibiotics from Gliding Bacteria, LII. Thiangazole, a New Tris(thiazoline) Derivative From Polyangium spec.: Absolute Configuration
Authors: Jansen Rolf , Schomburg Dietmar , Höfle Gerhard 
Published: July 2007

AbstractThe absolute configuration of thiangazole (1), which was previously derived by chemical degradation, was confirmed by X‐ray structure analysis. Energy minimization with MO and MM2 methods indicate, that the conformation of 1 in the crystal is controlled by crystal forces while various equally preferred conformations may be present in solution.
Bausteine von Oligosacchariden, CVII – Synthese von modifizierten Oligosacchariden der N‐Glycoproteine zur Untersuchung der Substratspezifität der N‐Acetylglucosaminyltransferase II
Authors: Paulsen Hans , Meinjohanns Ernst , Reck Folkert , Brockhausen Inka 
Published: July 2007

Building Units of Oligosaccharides, CVII. – Synthesis of Modified Oligosaccharides of N‐Glycoproteins for Substrate Specificity Studies of N‐Acetylglucosaminyltransferase IISeveral modified derivatives of the tetrasaccharide β‐D‐GlcNAc‐(1→2)‐α‐D‐Man‐(1→3)‐[α‐D‐Man‐(1→6)]‐β‐D‐Man‐octyl (1) were synthesized for substrate specifity studies of N‐acetylglucosaminyltransferase II (GlcNAcT II). The hydroxyl groups at C‐3, C‐4 or C‐6 of the α(1→6)‐linked Man residue and the hydroxyl groups at C‐3 and C‐6 of the α(1→3)‐linked Man were replaced by deoxy groups. All five tetrasaccharides were synthesized by a block synthesis by using deoxy saccharide residues. The trichloroacetimidate method was particulary successful for synthesizing the glycosidic linkages. The modified compounds have been tested as substrates for N‐acetylglucosaminyltransferase II (GlcNAcT II) from rat liver. The substrate specificity of GlcNAcT II will be discussed.
Bausteine von Oligosacchariden, CVIII. Synthese von modifizierten Oligosacchariden der N‐Glycoproteine zur Untersuchung der Substratspezifitäten der N‐Acetylglucosaminyltransferasen III bis VI
Authors: Paulsen Hans , Meinjohanns Ernst , Reck Folkert , Brockhausen Inka 
Published: July 2007

Building Units of Oligosaccharides, CVIII. – Synthesis of Modified Oligosaccharides of N‐Glycoproteins for Substrate Specificity Studies of N‐Acetylglucosaminyltransferase III to VIThe pentasaccharide β‐D‐GlcNAc‐(1→2)‐α‐D‐Man‐(1→3)‐[β‐D‐GlcNAc‐(1→2)‐α‐D‐Man‐(1→6)]‐β‐D‐Man‐octyl (3) and a series of modified derivatives of this compound were synthesized. The 4‐OH group of the β‐Man residue, the 3‐OH or 4‐OH group of the α‐(1→3)‐linked Man residue or the 6‐OH group of the α(1→6)‐linked Man residue were replaced by deoxy groups. The modified pentasaccharides were synthesized by a block synthesis using functionalized deoxy saccharide residues. Glycosylation reactions were achieved by the trichloroacetimidate method. These pentasaccharides are useful for substrate specificity studies of N‐acetylglucosaminyltransferases III to VI (GlcNAcT III to VI). The substrate specificity of GlcNAcT V will be discussed since this activity has been found to be increased in malignancies.
Synthese und Struktur Phenyl‐substituierter Bicyclo[3.3.1]nonene
Authors: Quast Helmut , Knoll Katja , Peters Eva‐Maria , Peters Karl , von Schnering Hans Georg 
Published: July 2007

Synthesis and Structure of Phenyl‐Substituted Bicyclo[3.3.1]nonenesAddition of one mole of phenyllithium to bicyclo[3.3.1]nonane‐2,6‐dione (5) affords the hydroxy ketone6besides small amounts of the known diol7. Dehydration of this mixture by sulfuric acid in acetic acid yields the unsaturated ketone8and the diene1which are separated by chromatography. Wolff‐Kishner reduction of8furnished the hydrocarbon2. In the same way, the known ketonesexo‐ andendo‐10are converted into4. The preferential formation of the less stableendo‐10is interpreted in terms of the relative stability of the conformations required in the intramolecular aldol reaction of diketone9. The conformations of4, 8,exo‐ andendo‐10are determined by X‐ray diffraction analyses. Vicinal proton coupling constants are calculated from torsional angles and compared to those determined in solutions by high‐field NMR spectroscopy.
Herstellung von α‐verzweigten Phenylalaninen und von 1,1‐disubstituierten Ethylendiaminen über chirale Imidazolidinone und Oxazolidinone aus Glycin – präparative und mechanistische Aspekte
Authors: Seebach Dieter , Gees Thomas , Schuler Franz 
Published: July 2007

Preparation of α‐Branched Phenylalanines and of 1,1‐Disubstituted Ethylenediamines via Chiral Imidazolidinones and Oxazolidinones of Glycine – Preparative and Mechanistic AspectsTo test the structural prerequisites for a new carbanionoid rearrangement of 3‐methyl‐2‐pivaloyl‐1,2,3,4‐tetrahydroisoquinoline‐3‐carboxylic acid to N‐(t‐butoxycarbonyl)‐1‐amino‐2‐methylindan‐2‐carboxylic acid (A → B), various α‐branched phenylalanines (C) were required. Geminal dialkylation of the chiral glycine building block Boc‐BMI (1) occurs in excellent yields and selectivities and can be carried out in a one‐pot procedure (products 2–10). However, phenylalanines with methoxy groups on the benzene ring and α‐branching by substituents larger than methyl cannot be set free by hydrolysis of the corresponding imidazolidinones, which, on the other hand can be reduced through N‐methyl amino acid amides (13–15) to geminally disubstituted N‐methyl‐ethylenediamines (16–18). A series of 2‐t‐butyl‐5‐oxo‐1,3‐oxazolidin‐3‐carboxylates (19–27) was prepared and could be resolved on ChiraSphere, Chiralcel OD, and Pirkle columns (Table 1). Alkylation (Me, Et, Bu), allylation, and benzylation of the rac‐oxazolidinones lead to trans‐disubstituted products (29–43) which were alkylated a second time (products 44–51); yields and selectivities are satisfactory (Table 2). Hydrolysis of 4,4‐dibenzyl‐substituted oxazolidinones to the amino acid derivatives is possible (examples 52–54). – Comparison of the methylation selectivities of seven 2‐t‐butyl‐1,3‐oxazolidin‐5‐one Li‐enolates bearing different N‐acyl groups (Figure 1) and an X‐ray crystal structure analysis of a phenol carbamate (26, Figure 2 and Table 3) show that our previous mechanistic model obtains: t‐butyl in the COR group gives the poorest selectivity (3:1), O‐phenyl the highest (>50:1). This is compatible with the view that the acylgroups (on pyramidalized nitrogens!) in these heterocyclic acetals occupy one face of the average plane of the rings, and the substituents on the acetal center (here t‐Bu) the other one (Figure 1).
Michael Addition of Malononitrile to α‐Acetylcinnamamides
Authors: Martín Nazario , Martínez‐Grau Angeles , Seoane Carlos , Marco José L. , Albert Armando , Cano Félix H. 
Published: July 2007

AbstractThe reaction of α‐acetylcinnamamides 7a–e with malononitrile using piperidine as the catalyst is described. When one or two equivalents of malononitrile are used, the 2‐amino‐4H‐pyran 6a or the polyfunctionalized carbocycles 9b–e, respectively, can be isolated as major products, depending on the experimental conditions. Compounds 9b–e apparently arise from a sequential Michael plus Knoevenagel addition of two molecules of malononitrile followed by Thorpe cyclization. The structure of 9b was determined by an X‐ray crystallographic analysis, which revealed a twisted cyclohexadiene ring with a characteristic crystal packing.
Carotenoids and Degraded Carotenoids, VIII – Synthesis of (+)‐Dihydroactinidiolide, (+)‐ and (−)‐Actinidiolide, (+)‐ and (−)‐Loliolide as well as (+)‐ and (−)‐Epiloliolide
Authors: Mori Kenji , Khlebnikov Vladimir 
Published: July 2007

AbstractEnantiomerically pure (S)‐2,4,4‐trimethyl‐2‐cyclohexen‐1‐ol (1) was efficiently converted into four degraded lactonic carotenoids: (S)‐dihydroactinidiolide (5), (S)‐actinidiolide (9), (6S,7aR)‐loliolide (11) and (6S,7aS)‐epiloliolide (12). (R)‐Actinidiolide (9), (6R,7aS)‐loliolide (11) and (6R,7aR)‐epiloliolide (12) were also prepared from (R)‐1.
1‐[1,7‐dicarba‐closo‐dodecaboran(12)‐1‐yl]aldoses: Novel Boron Neutron Capture Candidates
Authors: Dahlhoff Wilhelm V. , Bruckmann Joachim , Angermund Klaus , Krüger Carl 
Published: July 2007

AbstractMonolithiated 1,7‐dicarba‐closo‐dodecaborane(12) reacts withO‐isopropylidene derivatives ofD‐erythrono‐1,4‐lactone (1),L‐mannono‐1,4‐lactone (3) and with tetra‐O‐trimethylsilylatedD‐glucono‐1,5‐lactone (2) andD‐gulono‐1,4‐lactone (4) to give the title compounds after deprotection. An X‐ray structure analysis of the protectedL‐mannofuranose carborane derivative9reveals that the more stable anomer has the β‐Lconfiguration.
Synthese halogenierter Benzyl‐ und Benzoylpyrrole
Authors: Renneberg Bernd , Kellner Michael , Laatsch Hartmut 
Published: July 2007

Synthesis of Halogenated Benzyl‐ and BenzoylpyrrolesSeveral halogenated aroyl‐1H‐pyrroles of type 2, 14 and 19 are synthesized by reaction of aroylchlorides with pyrrolylmagnesium bromide, bromination or iodination of the pyrrole ring and demethylation with boron tribromide. Furthermore, the synthesis of the naphthylpyrrole 19b was performed by analogy with the synthesis of 1. Their antibiotic and cytotoxic activity is compared with 1, an antibacterial, enzyme‐inhibitory and cytotoxic compound, isolated from the marine bacterium Alteromonas luteoviolaceus.
Steroids, LII. Configurational Analysis of 16‐Methyl‐19‐nortestosterone Derivatives
Authors: Meskó Eszter , Dombi György , Lukács Ferenc , Schneider Gyula 
Published: July 2007

AbstractThe four possible stereoisomers of 3‐methoxy‐16‐methyloestra‐1,3,5(10)‐trien‐17‐ol (1, 2, 3, 4) were converted into the corresponding 16‐methyl‐19‐nortestosterone analogs (5, 6, 7, 8), which were characterized by their 1H‐ and 13C‐NMR spectra. The coupling constants J16,17 and the characteristic 13C signals (C‐12, C‐17, C‐18, 16‐CH3) clearly confirmed the configurations at C‐16 and C‐17.
Synthesen von α‐Aminophosphonsäuren aus N‐Ethoxyiminium‐Salzen, II
Authors: Shatzmiller Shimon , Neidlein Richard , Weik Christian 
Published: July 2007

Syntheses of α‐Aminophosphonic Acids from N‐Ethoxyiminium Salts, IINitrones 2 obtained from aldehydes 1 are used for the synthesis of N‐ethoxyiminium salts 3. These react with several esters of hydrogen phosphite 4 to give the N‐methyl α‐amino phosphonic esters 5 to 13. The N‐benzyl α‐amino phosphonic esters 24 and 25 can be obtained by the same procedure. Hydrogenolysis and ester hydrolysis afford the α‐amino phosphonic acids 14 as well as 26 and 27, respectively.
Multidimensional NMR Techniques for the Elucidation of Oligosaccharide Structures: Verbascosaponin and a Further Saponin from Wool Flower
Authors: Schröder Harald , Haslinger Ernst 
Published: July 2007

AbstractThe application of 1D selective, 2D and 3D NMR techniques to the structure elucidation of verbascosaponin (1) is demonstrated. Combinations of ROESY and TOCSY are powerful tools. Each of these multidimensional ROESY‐TOCSY and TOCSY‐ROESY experiments provides detailed information about the sequence of oligosaccharide structures and the positions of glycosidation. The structure of a further saponin 2 from the officinal drug Flores Verbasci is determined as 3β‐O‐{α‐L‐rhamnopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→3)‐[β‐D‐glucopyranosyl‐(1→2)‐]‐β‐D‐fucopyranosyl}‐13β,28‐epoxyolea‐11‐ene‐16α,23α‐diol.