bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total synthesis of mycinolide‐V
Authors: Hoffmann Reinhard W. , Ditrich Klaus 
Published: July 2007

AbstractThe first synthesis of mycinolide‐V (1) is reported. 1 is the aglycon of mycinamycin‐V, a 16‐membered macrolide antibiotic. The synthesis starts from a C‐3/C‐9 segment, which has been extended to a C‐1/C‐10 building block, and subsequently condensed with a C‐11/C‐17 segment.
Biologically active glycosides from asteroidea, XIX. Glycosphingolipids from the starfish Acanthaster planci 4. Isolation and structure of five new gangliosides
Authors: Kawano Yasuhiro , Higuchi Ryuichi , Komori Tetsuya 
Published: July 2007

AbstractFive new gangliosides — acanthaganglioside A (1), B (2), C (3), D (4) and E (5) — were purified from the water‐soluble lipid fraction of the chloroform/methanol extract of the starfish Acanthaster planci. Based on chemical and spectroscopic data, the structures of 1–5 were elucidated. The gangliosides consist of one homogeneous long‐chain base, five or six sugars and different fatty acids. Reversed‐phase HPLC using methanol/ammonia/water as solvent was effective in isolating these gangliosides, showing the very close similarity in their structures. Negative FAB mass spectrometry provided important information both on the structure of the sugar moiety and on the molecular mass of the gangliosides. Partial hydrolysis by hot pyridine/water or hot water was useful for structure elucidation of the complex oligosaccharide moieties.
Synthese von (±)‐2‐Oxo‐seychellen und (±)‐2‐Oxo‐4‐epi‐seychellen
Authors: Spitzner Dietrich , Klein Iris 
Published: July 2007

Synthesis of (±)‐2‐Oxo‐seychellene and (±)‐2‐Oxo‐4‐epi‐seychelleneAprotic Michael additions, which generate the functionalized bicyclo[2.2.2]octane 8 from ethyl 2‐methyl‐2,3‐butadienoate (10) and the lithium cyclohexadienolate 9a, are the key steps in the synthesis of 6 (and its 4‐epimer). 6 was made from 8 in 10 steps. The alternative Diels‐Alder reaction of 10 with the trimethylsiloxycyclohexadiene 9b gave exclusively the [2+2] adduct 14 as a 1:1 mixture of diastereomers.
Palladium‐katalysierte Ringschlußreaktionen zu Benzofuranen: ein neuer und effektiver Zugang zu Azacumöstrolderivaten
Authors: Stadlbauer Wolfgang , Laschober Rita , Kappe Thomas 
Published: July 2007

Palladium‐Catalyzed Ring Closure Reactions to Benzofuranes: A New and Effective Approach to AzacoumestrolsAzacoumestans (benzofuro[3,2‐c]quinolinones) 4 have been synthesized using the following three methods: ring closure of 3‐aryl‐4‐hydroxy‐2‐quinolones 3a–e by Pd‐catalyzed cyclodehydrogenation, ring closure of 3‐hydroxy‐3‐aryl‐2,4‐quinolinediones 5 by acid‐catalyzed cyclodehydratation, or ring closure of 4‐aryloxy‐3‐iodo‐quinolones 8, which are obtained by rearrangement of iodonium ylides 7, by palladium‐mediated cyclodehydrohalogenation. Only the latter reaction yielded the coumestrol analog dimethoxy derivatives 4c, d, which have been transformed into the hydroxy and acetoxy derivatives 9, 10.
New eudesmane derivatives from Artemisia tournefortiana
Authors: Sanz Juan Francisco , Marco Juan Alberto 
Published: July 2007

AbstractExtraction of the aerial parts of Artemisia tournefortiana Reichb. yields a new cis‐eudesmanolide 4 and three new eudesmane acids 7, 8, and 10, together with several known compounds. Their structures were deduced by spectroscopic and chemical methods.
Solvolysis of N‐(Chlorosulfinyl)diarylketimines
Authors: Al‐Talib Mahmoud , Tashtoush Hasan 
Published: July 2007

AbstractN‐(Chlorosulfinyl)diarylketimines 1a–c readily react with alcohols, phenols and thiophenol to give good yields of dialkyl sulfites, diaryl sulfites and dithiosulfites, respectively, besides (diarylmethylene)ammonium chlorides 3a–c. The reactions of 1a with water and carboxylic acids have also been studied.
Transesterification during glycosylation promoted by silver trifluoromethanesulfonate
Authors: Ziegler Thomas , Kováč Pavol , Glaudemans Cornelis P. J. 
Published: July 2007

Abstract2‐O‐[2,2,2‐D3]Acetyl‐3,4,6‐tri‐O‐acetyl‐α‐D‐galactopyranosyl bromide (3) was prepared and used as the glycosyl donor in studying the silver trifluoromethanesulfonate‐promoted reaction with methyl 2,3,4‐tri‐O‐benzoyl‐β‐D‐galactopyranoside (4) and methyl 2,4,6‐tri‐O‐benzoyl‐β‐D‐galactopyranoside (7). In addition to the expected β‐linked disaccharides, methyl 6‐O‐[2,2,2‐D3]acetyl‐2,3,4‐tri‐O‐benzoyl‐β‐D‐galactopyranoside (6) and methyl 3‐O‐[2,2,2‐D3]acetyl‐2,4,6‐tri‐O‐benzoyl‐β‐D‐galactopyranoside (9), respectively, were formed. The latter compounds were isolated from the reaction mixture and their structures were confirmed based on spectral data. Thus, it has been proven that, with fully acetylated glycosyl halides as glycosyl donors, in silver trifluoromethanesulfonate‐promoted couplings, O‐acetylation of the nucleophile occurs as a side reaction, the acetyl group involved originating from position 2 of the glycosyl halide.
Reactions of organic anions, 173. Oxidative cross‐coupling of enolates with nitronate anions promoted by chloride anions
Authors: Wróbel Zbigniew , Ma̧kosza Mieczysław 
Published: July 2007

AbstractNitronate anions derived from primary and secondary nitroal‐kanes undergo cross‐coupling reactions with diethyl alkylmalonate anions in alcohol/DMF solution when treated with silver nitrate. A catalytic amount of chloride ions is necessary to promote selective reaction.
Structural variations of N‐acetylneuraminic acid, 14. Synthesis of the β‐methyl ketosides of 4‐oxo‐, 7‐oxo‐, and 8‐oxo‐N‐acetylneuraminic acid and the corresponding 7,7‐ and 8,8‐dimethoxy derivatives their behaviour towards CMP‐sialate synthase
Authors: Hartmann Michael , Christian Rudolf , Zbiral Erich 
Published: July 2007

AbstractThe 4‐, 7‐, and 8‐oxo‐sialic acid β‐methyl ketosides 7, 10a, and 11a were obtained by transformation of easily available derivatives of N‐acetylneuraminic acid (1a). The carbonyl migration from C‐7 to C‐8 can be carried out under well‐defined conditions with formation of the ketone 11b. Starting from 7‐ and 8‐ketones 17 and 20 the corresponding dimethyl acetals are prepared. The 4‐ketone 7 behaves as a moderate competitive inhibitor of CMP‐sialate synthase [EC 2.7.7.43], whereas the 8‐ketone 11a, the 8,8‐dimethyl acetal 19, and the 7,7‐dimethyl acetal 23 prove not to be inhibitors of this enzyme. The 7‐ketone 10a was not tested because of instability under test conditions at pH 8.5.
Regioselectivity of the amination of some nitroisoquinolines by liquid ammonia/potassium permanganate
Authors: Woźniak Marian , Barański Andrzej , Nowak Krystyna , Poradowska Henryka 
Published: July 2007

Abstract5‐ and 8‐Nitroisoquinoline and some of their derivatives are aminated in a liquid ammonia solution of potassium permanganate to yield the corresponding 6‐ and 7‐amino compounds. From 5,7‐dinitroisoquinoline the 6,8‐diamino derivative is obtained; 1‐nitroisoquinoline has been found to be unreactive. FMO calculations made for a few nitroisoquinolines confirm the experimentally observed regioselectivity of the amination.
Structural variations of N‐acetylneuraminic acid, 15. Synthesis of 9‐deoxy‐, 7,9‐dideoxy‐, and 4,7,9‐trideoxy‐N‐acetylneuraminic acid and their behaviour towards CMP‐sialate synthase
Authors: Schreiner Erwin , Christian Rudolf , Zbiral Erich 
Published: July 2007

AbstractThe methyl ester of N‐acetylneuraminic acid β‐methyl ketoside (Neu5Ac1Me‐2β‐Me) (1) is used as common starting material for the synthesis of the title compounds. Combined derivatization reactions with reagents thiophosgene, p‐cresol, benzoyl chloride, and acetic anhydride/pyridine lead to the thiocarbonate derivatives 2, 6–8, and 12. Further transformation with iodomethane yields the 9‐iodo compounds 3, 9, and 13, which are reduced by tributyltin hydride to the deoxy derivatives 4, 10, and 14. Hydrolysis of 14, 10, and 4 affords the desired 9‐deoxy, 7,9‐dideoxy‐, and 4,7,9‐trideoxy‐N‐acetylneuraminic acids 15 (9‐d‐Neu5Ac), 11 (7,9‐d2‐Neu5Ac), and 5 (4,7,9‐d3‐Neu5Ac), respectively. — The sialic acid analogues 11 and 5 were activated by CMP‐sialate synthase [E,C.2.7.7.43] to an extent of 30–40 and 50–60%, respectively, relative to N‐acetylneuraminic acid.
Unusual amination by cleavage of an exocyclic C  N linkage with formamide
Authors: Ram Vishnu J. , Kushwaha Dinesh S. 
Published: July 2007

AbstractSynthesis of various 3‐alkyl‐2‐(1‐pyrazolyl)‐4(3H)‐quinazolinones (1a‐g) and their amination with formamide under different reaction conditions are described.
Synthesis of angular annulated heteroaromatic quinazolino‐[3,2‐a] quinazolines
Authors: Ram Vishnu J. , Kushwaha Dinesh S. 
Published: July 2007

AbstractA facile synthesis of various 6‐alkyl‐5H‐quinazolino[3,2‐α]‐quinazoline‐5,12(6H)‐diones 7–14 is described, by thermal cyclization of 3‐alkyl‐2‐(methylthio)quinazoline‐4(3H)‐ones 2 with 2‐aminobenzoic acid or 3‐aminonaphthoic acid at 180–190°C.
Reduktive Cyclisierungen mit Ketylen von Bicyclo[2.2.2]octanonen
Authors: Spreitzer Helmut , Kalchhauser Hermann 
Published: July 2007

Reductive Cyclizations of Ketyls of Bicyclo[2.2.2]octanonesDepending on the reaction conditions the ketyls 2a/b of bicyclo[2.2.2]octanones 1a/b cyclize to the alcohols 3a/b and 4a/b, respectively.
A simple high‐yielding synthesis of spiro[cyclopropane‐1,2′‐steroids]
Authors: Desai Umesh R. , Trivedi Girish K. 
Published: July 2007

AbstractA high‐yielding synthesis of biologically active spiro‐[cyclopropane‐1,2′‐steroids] with a Δ4′‐3′‐one moiety by using the Simmons Smith reaction is described. 2‐Methylene‐4‐en‐3‐one steroids are treated with methylene iodide (ratio 1:1).
Sequential analysis of oligosaccharide structures by modern NMR techniques
Authors: Haslinger Ernst , Korhammer Siegfried , Schubert‐Zsilavecz Manfred 
Published: July 2007

AbstractSequential analysis of oligosaccharide structures can be achieved by semiselective NMR‐pulse techniques. Gaussianshaped pulses combined with multistep‐relayed coherence transfer and NOE have been used to determine the sequence and assign the carbohydrate resonances of lanatoside C.
Chiral building blocks for the synthesis of nitrogen‐containing natural products, 5. The enantioselective synthesis of optically active, benzene nucleus‐substituted 1‐phenylethylamines from the corresponding acetophenones
Authors: Bringmann Gerhard , Geisler Joerg‐Peter , Geuder Torsten , Künkel Georg , Kinzinger Lioba 
Published: July 2007

AbstractAn efficient two‐step procedure for the synthesis of enantiomerically pure, benzene nucleus‐substituted 1‐phenylethylamines 1 is described, with predictable absolute configuration at the stereogenic center: Imine formation from the substituted acetophenones 6 with (S)‐ or (R)‐1‐phenylethylamine [(S)‐7 or (R)‐7] and subsequent hydrogenation of the resulting Schiff bases 8 over Raney nickel leads to the secondary amines 9 and 10 in high diastereoselectivities. These dibenzylamines are cleaved regioselectively, usually next to the less substituted aromatic ring, giving the desired chiral 1‐phenylethylamines 1 in high yields and enantiomeric purities. Scope and limitations of this new and facile approach to the versatile building blocks 1 are reported.
Organoboron monosaccharides, XVI. Selective syntheses of the methyl α‐D‐furanosides of Lyxose and Mannose using ethyl(dimethoxy)borane
Authors: Dahlhoff Wilhelm V. , Fenzl Wolfgang , Köster Roland 
Published: July 2007

AbstractEthyl(dimethoxy)borane is prepared by a two‐step method involving reaction of triethylboroxin with 1,4‐butanediol in a molar ratio of 1:3 to give oligomeric 1,4‐butanediyldioxy‐ethylboranes which are then treated with methanol. D‐Lyxose (1) reacts selectively with ethyl(dimethoxy)borane in the presence of acidic ion exchange resin to form methyl 2,3‐O‐ethylboranediyl‐α‐D‐lyxofuranoside (2) which is deboronated to give methyl α‐D‐lyxofuranoside (4). Similarly, D‐mannose (6) reacts to give methyl 2,3:5,6‐bis‐O‐ethylboranediyl‐α‐D‐mannofuranoside (7), the deprotection of which yields methyl α‐D‐mannofuranoside (8).
On the cyclization to the elusive amino‐4H‐pyran ring some new facts
Authors: Martín‐León Nazario , Quinteiro Margarita , Seoane Carlos , Soto José L. 
Published: July 2007

AbstractThe reaction of 2‐indolinone (1) with arylidenemalononitriles (2) or benzylidenecyanoacetamide (9) yields the Michael adducts 3, 10 and the spiro compound 4a. No cyclization to a 4H‐pyran ring is achieved. Similar results are obtained from the unsaturated lactone 11 and the carbonyl compound 13. In contrast, 1,3‐cyclohexanedione (15) leads to the fused 2‐amino‐4H‐pyran 16 upon reaction with benzylidenemalononitrile (2).
Organic azides in heterocyclic synthesis, 11. Ring closure of 3‐acetyl‐4‐azido‐2‐quinolones to isoxazolo[4,3‐c]quinolones
Authors: Roschger Peter , Stadlbauer Wolfgang 
Published: July 2007

AbstractThermolysis of the 3‐acetyl‐4‐azido‐2‐quinolone 6, which was obtained from the corresponding 4‐tosyloxy derivative 5, afforded the ring closed isoxazoloquinolone 7 in good yield.
The complex reaction of acetohydrazides with unsaturated diketones: Alternative cyclizations to 1,2‐diazepin‐3‐ones and pyrazolo[3,4‐b]pyridines
Authors: Alonso Paloma , Martín‐León Nazario , Quinteiro Margarita , Seoane Carlos , Soto José L. 
Published: July 2007

AbstractThe reaction of 2‐cyanoacetohydrazide (1) and 2‐(ethoxycarbonyl)acetohydrazide (26) with unsaturated 1,3‐diketones leading with moderate yields to 1,2‐diazepinones (3, 23, 24) and pyrazolo[3,4‐b]pyridines (5, 15, 20, 25) together with the corresponding acetohydrazones have been studied. The reaction course depends on the temperature and the relative reactivity of the carbonyl groups of the starting materials. When one of these carbonyl groups is less reactive (benzoyl or ethoxycarbonyl groups), the reaction does not yield diazepinones but only pyrazolo[3,4‐b]pyridines and/or acetohydrazones.
Oxime ethers as potential juvenoids: Synthesis of optical isomers
Authors: Wimmer Zdenêk , Vašíčková Soňa , Šaman David , Romaňuk Miroslav 
Published: July 2007

AbstractTwo racemic juvenoids 5 and 6 and their optical isomers 10, 11, 17 and 18 having chiral centres in the aliphatic side chain were synthetized. The second chiral centre in the molecules remained racemic in all derivatives prepared. The absolute configurations of the optically active centres of the enantiomers were determined on the basis of the 1H‐NMR spectral evaluation of the diastereoisomeric MTPA esters 12, 13, 19 and 20 derived from the intermediate alcohols 8 and 15. The optical purity was established by an HPLC analysis of the corresponding MTPA esters. The 1H‐NMR spectra of all compounds as well as the CD spectra of all chiral isomers were measured and discussed.
Glycosylation of 2,3‐diphenylindole and derivatives — Synthesis of O‐, N‐, and C‐glycopyranosides
Authors: El‐Desoky El‐Sayed I. , Abdel‐Rahman Hassan A. R. , Schmidt Richard R. 
Published: July 2007

AbstractReaction of different glycosyl donors with 5‐hydroxy‐N‐methyl‐2,3‐diphenylindole (1C) led only to O‐glycosylation (compounds 6a–c and 8c‐α,β). Depending on the O‐protection of the glycosyl donors (2a–c, 3b, 4c), the β‐products were obtained mainly or exclusively. The corresponding N‐unsubstituted indole 1B and donors 2b and 5a, respectively, also yielded only O‐glycosylated products (compounds 11b and 13a). Depending on the glycosyl donor (2a or 2c), the N‐unsubstituted 5‐methoxy‐2,3‐diphenylindole (1A) led to N‐ and/or C‐glycosides (compounds 16a, 14a‐α,β, and 14c‐α,β). The structures were assigned with the help of 1H‐NMR data of these products or their derivatives.
Verbesserte Synthese von N1‐Pyridylthiaminpyrophosphat, einem coenzymatisch aktiven Analogon des Thiaminpyrophosphates
Authors: Neef Holger , Golbik Ralph , Fahlbusch Barbel , Schellenberger Alfred 
Published: July 2007

Improved Synthesis of N1‐Pyridylthiamine Pyrophosphate, a Coenzymatically Active Analog of Thiamine PyrophosphateOur previously published synthesis of the N1‐pyridyl analog 1b of thiamine pyrophosphate6) is improved resulting in a remarkably higher yield. Key reaction of this new synthetic pathway is the oxidative degradation of 5‐acetylpyridine 8 to the 5‐carboxylic acid 11 via the pyridinium compound 10. Improved preparations of other intermediates are also described. The N1‐pyridylthiamine pyrophosphate analog 1b has been separated and purified by ion exchange chromatography on Sephadex A‐25.
Neue Synthesewege zu Thiophosphatidylcholin mit CSP‐Bindung
Authors: Mlotkowska Barbara , Markowska Anna 
Published: July 2007

New Synthetic Routes to Thiophosphatidylcholine with C  S  P BondA simple and effective synthesis of thiophosphatidylcholine (4) based on phosphorylation of 2,3‐di(stearoyloxy)‐1‐propa‐nethiol (1a) or 2,3‐di(stearoyloxy)‐1‐(trimethylsilyl)‐1‐propane‐thiol (1b) with 2‐chloro‐2‐oxo‐1,3,2‐dioxaphospholane (2) followed by ring opening of the resultant product 3 is described.
Natural product chemistry, 139. Synthesis of the natural coumarins (E)‐suberenol, cyclobisuberodiene and two other related new coumarins
Authors: Reisch Johannes , Herath H. M. T. Bandara , Kumar N. Savitri 
Published: July 2007

AbstractThe total synthesis of (E)‐Suberenol (1) was carried out under the conditions of palladium‐catalysed Heck condensation. Two other new coumarins, (E)‐7‐methoxy‐6‐(3‐methyl‐1,3‐butadienyl)coumarin [(E)‐suberodiene] (3) and (E)‐7‐methoxy‐6‐(3‐methyl‐1‐butenyl)coumarin [(E)‐suberenene] (4) and cyclobisuberodiene (2) were synthesised from (E)‐suberenol.
Vergleichende Untersuchung zur Diastereoselektivität der O‐Methylierung von sterisch behinderten β‐Ketocarbonsäureestern und ihren Enolen
Authors: Buß Monika , Meier Herbert 
Published: July 2007

Diastereoselectivity of the O‐Methylation of Sterically Hindered β‐Ketocarboxylates and Their EnolsThe enols 1a, b, and 1c, which exists almost completely in the keto form, have been methylated at the oxygen atom with diazomethane. The regioselective reaction can be catalyzed by methanol, but may loose in that case the diastereoselectivity. A comparison with the methylation of the enolates by iodomethane is discussed.
Thermal degradation of glycosides, III. Degradation of cardenolide glycosides
Authors: Kim Youn Chul , Higuchi Ryuichi , Komori Tetsuya , Abe Fumiko , Yamauchi Tatsuo 
Published: July 2007

AbstractThe thermal degradation of cardenolide glycosides consisting of different sugar moieties and aglycones was examined. On simple heating, the sugar—aglycone linkage of cardenolide glycosides having 2,6‐dideoxy sugar moieties in readily cleaved, to afford their genuine aglycones. On the contrary, cardenolide glycosides possessing 6‐deoxy sugar moieties are resistant to the degradative reaction. Besides the fission of the glycosidic linkages, some interesting reactions also took place. The pyrolyzed products were isolated by chromatography, and the structures were elucidated by spectroscopic evidence.
Transformations starting from biotechnologically available materials, I. A convenient preparative route to 1‐oxa‐5‐azaspiro[2.4]heptane Systems
Authors: Svêtlík Jan , Veverka Miroslav 
Published: July 2007

AbstractA simple, efficient procedure for the conversion of N‐arylitaconimides 3a—f into novel 5‐aryl‐1‐oxa‐5‐azaspiro[2.4]‐heptane‐4,6‐diones 4a–f using peroxytrifluoroacetic acid is described.
Prolin‐benzylester als chirale Hilfsgruppen in asymmetrischen 1,3‐dipolaren Cycloadditionen mit Nitriloxiden
Authors: Waldmann Herbert 
Published: July 2007

Proline Benzyl Esters as Chiral Auxiliaries in Asymmetric 1,3‐Dipolar CycloadditionsN‐Acryloylproline benzyl ester (1b) reacts with nitrile oxides at temperatures from −78 to 0°C to give isoxazolines 4/5 with diastereomeric ratios of ca. 3:1 and with the (5S) isomer as the predominating. The corresponding N‐methacryloylproline benzyl ester (1c) gives inferior results. The diastereoselectivity is not influenced by the temperature and the substituents of the nitrile oxides. To prove the absolute configuration of the predominating stereoisomer, a reaction sequence is developed which makes use of an enantioselective hydrolysis with pig liver esterase as the key step to generate an optically active isoxazoline with known stereochemistry. In the reactions of the N,N′‐fumaroylbis(proline benzyl ester) (11) with the nitrile oxides the chiral auxiliaries display synergistic stereodirecting influences and, as a consequence, the cycloadducts 12/13 are formed at −78°C with ratios of ca. 9:1.
Biosynthese von Naturstoffen mit einer P  C‐Bindung, V. Das Oxiran‐Sauerstoff‐Atom des Fosfomycins entstammt nicht dem Luft‐Sauerstoff
Authors: Hammerschmidt Friedrich , Bovermann Günter , Bayer Karl 
Published: July 2007

Biosynthesis of Natural Products with a P  C Bond, V. — The Oxirane Oxygen Atom of Fosfomycin Is not Derived from Atmospheric OxygenFosfomycin (1) in the culture broth of Streptomyces fradiae was transformed into (amino hydroxypropyl)phosphonic acids 12 and 13. The main product 12 was isolated by ion‐exchange chromatography. Streptomyces fradiae grown in an 18O2‐enriched atmosphere produced unlabelled fosfomycin. For comparison 18O‐labelled diastereomeric (2‐amino‐1‐hydroxypropyl)phosphonic acids 16 and 17 showing an α shift of 0.025 ppm in the 13CC‐NMR spectrum were prepared starting from Boc‐L‐alaninal. (Z)‐1‐[2,3‐2H2]Propenylphosphonic acid was not incorporated into 1. D‐[6,6‐2H2]Glucose afforded 12 with 16% deuterium at C‐1.
Reactions of nitrile oxides and nitrile imines with 4‐arylidene‐2‐phenyl‐5(4H)‐thiazolones
Authors: Coutouli‐Argyropoulou Evdoxia , Thessalonikeos Elisavet 
Published: July 2007

AbstractNitrile oxides 2a, b and nitrile imines 2c–e are added to the C  C bond of 4‐arylidene‐2‐phenyl‐5(4H)‐thiazolones 1 to afford spiro‐isoxazolines 3a–d and spiro‐pyrazolines 3e–j, respectively. The cycloaddition reactions are regioselective and only one of the two possible regioisomers is isolated. Reactions of the cycloadducts with nucleophiles lead to isoxazole and pyrazole derivatives 8 and 10 by opening of the thiazolone ring.
Preparative‐enzymatic formation of cytidine 5′‐monophosphosialate by integrated cytidine 5′‐triphosphate regeneration
Authors: Thiem Joachim , Stangier Peter 
Published: July 2007

AbstractThe preparative formation of cytidine 5′‐triphosphate by an enzymatic process with adenylate kinase and pyruvate kinase is described. The enzymes may either be used free, in the “MEEC” technique, or immobilized on a synthetic copolymer of vinyl acetate and N,N′‐divinylethyleneurea (“VA‐Epoxy”). Cytidine 5′‐monophosphosialate synthase (preferably isolated from calf brain) and inorganic pyrophosphatase were used to prepare the activated neuraminic acid cytidine 5′‐monophosphosialate (CMP‐Neu5Ac) from CTP and neuraminic acid in good yield. Finally, both processes could be integrated and led to an in situ approach which, owing to moderate yields, requires further development.
Synthesis and properties of the enantiomers of the two artificial fragrances lilial and methylundecanal
Authors: Enders Dieter , Dyker Hubert 
Published: July 2007

AbstractThe enantiomers of the two artificial fragrances 3‐(4‐tert‐butylphenyl)‐2‐methylpropanal (lilial) and 2‐methylundecanal are synthesized with high enantiomeric purity using the SAMP/RAMP hydrazone method. The enantiomeric excesses are determined by HPLC via the corresponding SASP hydrazones. The olfactorial qualities of the enantiomers are described.
Synthesis of functionalized pyridines by michael addition of benzoyl(thioacetanilides) to arylmethylenemalononitriles and ethyl α‐cyanocinnamates
Authors: Bogdanowicz‐Szwed Krystyna , Lipowska Malgorzata , Rys Barbara 
Published: July 2007

AbstractThe synthesis of substituted 2‐thioxopyridines from benzoyl(thioacetanilides) 1 and arylmethylenemalononitriles or ethyl α‐cyanocinnamates 2 is described. The reaction of 1 with 2b, c gives rise to derivatives of tetrahydro‐ 5 and dihydro‐6‐thioxopyridines 6. A 4,5‐cis configuration of 5 is proposed on the basis of the analysis of the vicinal coupling constants.