bluuebunny/crossref_metadata_2025_split huggingface dataset:
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 21. Naphtho[2′,1′:4,5]thieno[2,3‐c]naphtho[1,2‐f]‐quinoline, naphtho[2′,1′:4,5]thieno[2,3‐c]naphtho[1,2‐f][1,2,4]‐triazolo[4,3‐a]quinoline and naphtho[2′,1′:4,5]thieno[2,3‐c]naphtho[1,2‐f]‐tetrazolo[1,5‐a]quinoline
Authors: Luo Jiann‐Kuan , Federspiel Ronald F. , Castle Raymond N. 
Published: March 2009

AbstractPhotocyclization of 3‐chloro‐N‐(3‐phenanthryl)naphtho[1,2‐b]thiophene‐2‐carboxamide (12) furnished only one of the two possible isomers, i.e., naphtho[2′,1′:4,5]thieno[2,3‐c]naphtho[1,2‐f]quinolin‐6(5H)‐one (13), which was further elaborated to yield the unsubstituted ring system 7, its triazole 8 and tetrazole 9. The structural confirmation of 7 was accomplished by the total assignment of its 1H and 13C nmr spectra utilizing the concerted two‐dimensional nmr spectroscopic experiments.
An improved synthesis of 2‐amino‐5‐[(4‐chlorophenyl)thio]‐4‐morpholinopyrimidine (BW 394U) — A potential antisenility agent
Authors: Samano Vicente , Styles Virgil L. , Chan Joseph H. 
Published: March 2009

AbstractThis paper describes the synthesis of 2‐amino‐5‐[(4‐chlorophenyl)thio]‐4‐morpholinopyrimidine (BW 394U, compound 4), a potential antisenility agent. The key intermediates 3a/3b were obtained from an in situ‐generated Vilsmeier‐Haack reagent that simultaneously protected the 2‐amino group prior to further manipulations. Displacement of the chloro group in 3a gave 4 in 40% yield and 4‐dimethylamino analogue 5. However, displacement of 3b with morpholine followed by treatment with aqueous base gave 4 in 74% yield.
Biologically active 1‐arylpiperazines. Synthesis of N‐[3‐(4‐aryl‐1‐piperazinyl)propyl] derivatives of benzoxazinone and benzoxazolinone
Authors: Kowalski Piotr , Majka Zbigniew , Kowalska Teresa , Mokrosz Maria J. , Duszynska Beata 
Published: March 2009

AbstractThe synthesis of new N‐[3‐(4‐aryl‐1‐piperazinyl)propyl] derivatives of 1H‐2,4‐benzoxazin‐3(4H)‐one (1a‐b), 2H‐1,4‐benzoxazin‐3(4H)‐one (2a‐b, 3a‐b and 4b), and benzoxazolin‐2‐one (5a‐b), as biologically active agents, is described.
The reaction of 2,4,5,6‐tetraaminopyrimidine with chalcones
Authors: Insuasty Braulio , Pérez Alfredo , González Diego , Quiroga Jairo , Meier Herbert 
Published: March 2009

AbstractThe reaction of the tetraaminopyrimidine 1 with the chalcones 2a‐f yields, in the presence of catalytic amounts of acetic acid, the 1H‐pyrimido[4,5‐b][1,4]diazepine derivatives 3a‐f. The cyclization process consists of a condensation reaction and a Michael type addition.
Studies on pyrrolidinones. Synthesis and cyclization of N‐[α‐naphthyl‐(3,4,5‐trimethoxyphenyl)‐methyl]pyroglutamic acid
Authors: Legrand Anne , Rigo Benoît , Hénichart Jean‐Pierre , Norberg Bernadette , Camus Fabrice , Durant FranÇOis , Couturier Daniel 
Published: March 2009

AbstractCondensation of trimethoxyphenyl naphthylcarbinol trimethylsilyl ether with methyl N‐trimethylsilyl‐pyroglutamate yields two separable esters. The Friedel‐Crafts cyclization of the acids obtained after saponification gives analogs of azapodophylloxin. Reduction and treatment of the obtained products with hydrobromic acid yields analogs of azatoxin.
Synthesis of vinca alkaloids and related compounds part 94. Epimerization of compounds with aspidospermane and D‐secoaspidospermane skeleton
Authors: Kalaus György , Szabó Lajos , Éles János , Szántay Csaba , Juhász Imre , Greiner IstvÁn , Brlik János , Kajtár‐Peredy Mária 
Published: March 2009

AbstractThe individual epimerization steps of vincadifformine (1), deethylvincadifformine isomers (2,3), their synthetic intermediates (4–13) as well as that of simpler compounds with D‐secoaspidospermane skeleton (15–17) were studied a) in protic medium (boiling deuteroacetic acidic) and b) under reductive (with sodium borodeuteride in boiling acetic acid, or with sodium borohydride in boiling deuteroacetic acid) conditions.
The photochemistry of 6‐phenanthridinecarbonitrile I. Product analysis
Authors: Vittimberga Bruno M. , Sears Donald F. 
Published: March 2009

AbstractWhen 6‐phenanthridinecarbonitrile (3) is irradiated at 2537 Å in neutral 9:1 2‐propanol/water, three major products are formed. These are dimethyl‐(6‐phenanthridinyl)methanol (4), phenanthridine (5) and 6,6′‐biphenanthridine (6). When benzophenone is present in the reaction mixture, diphenyl‐(6‐phenanthridinyl)‐methanol is also formed. 6‐Phenanthridinyl radical which is common to the formation of all these products, is formed by a monophotonic process involving hydrogen atom abstraction from an alcohol molecule by an excited state of 3. Unlike what is generally found with other nitrogen‐heterocycles, the photochemistry of 3 appears to involve only a π,π* singlet state. The fluorescence of 3 is quenched with the triplet quencher cis/trans‐piperylene as a function of the concentration of the diene without the accompaniment of an exci‐plex emission.
New 1,8‐peri‐annelated tricyclic quinolone antibacterials
Authors: Miao H. , Cecchetti V. , Tabarrini O. , Fravolini A. 
Published: March 2009

AbstractThe synthesis of new tricyclic quinolones, resulting from peri‐annelation of 1,2,4‐oxadiazine moiety at the N‐1/C‐8 position of the pharmacophoric quinolone nucleus, are described. None of the synthesized compounds showed interesting antibacterial activity in vitro against the tested strains, with the exception of Klebsiella pneumoniae which was susceptible to all the compounds at MIC values of 8 μg/ml.
Reactions of 3‐methylamino‐5‐phenylthiophene with α,β‐unsaturated esters and α,β‐unsaturated nitriles
Authors: Lee Jong Seok , Kim Kyongtae 
Published: March 2009

AbstractTreatment of 3‐methylamino‐5‐phenylthiophene with α,β‐unsaturated esters, i.e., methyl acrylate, (E)‐methyl crotonate, diethyl fumarate, diethyl maleate and ethyl propiolate, in tetrahydrofuran for several days at reflux gave 1‐methyl‐3,4‐dihydrothieno[2,3‐e]pyridin‐2‐ones 4 and/or 1‐methylthieno[2,3‐e]pyridin‐2‐ones 5, depending on the structure of the esters. On the other hand, the same reactions with α,β‐unsaturated nitriles such as acrylonitrile and tetracyanoethene, gave the corresponding thiophenes 7 and 10 bearing 2‐cyanoethyl and 1,2,2‐tricyanoethenyl groups at C‐2, respectively. The reaction with (Z)‐1,2‐dicyanoethene under the same conditions produced the corresponding thiophene 9 bearing the 1,2‐dicyanoethenyl group and 1,2‐dicyano‐5‐methylaminobiphenyl.
Synthesis of a novel purine‐containing heterocyclic ring system: 8,10‐Dimethylindolo[2′,3′:5,6][1,2,4]triazino[4,3‐f]purine‐9,11(8H, 10H, 13H)‐dione
Authors: Da Settimo Antonio , Primofiore Giampaolo , Da Settimo Federico , Simorini Francesca , Marini Anna Maria , La Motta Concettina , Taliani Sabrina 
Published: March 2009

AbstractThe preparation of a novel purine containing heterocyclic ring system, indolotriazinopurine, by the condensation of 8‐hydrazinotheophylline with 5‐substituted isatins via the intermediate hemiaminal and hydrazone derivatives, is described.
Synthesis of 2,5‐bis‐arylpyridines by [4 + 2] cycloaddition of 1,4‐bis aryl‐2‐aza‐1,3‐butadienes with electron‐poor dienophiles
Authors: Paparin Jean‐Laurent , Crévisy Christophe , Grée René , Toupet Loïc 
Published: March 2009

AbstractTetrahydropyridines 4a, 4b, 4c and pyridines 7a, 7b, 7c, 9a, 9b, 9c were synthesized by a [4 + 2] cycloaddition between 1,4‐bis aryl‐2‐aza‐1,3‐butadienes and electron‐poor dienophiles. Dimeric cycloadducts 6a, 6b, 6c, were also isolated indicating a competition between the expected Hetero Diels‐Alder and a dimerization process.
Studies on pyrazines. 36. A novel synthesis of 6‐(2‐hydroxyethyl)‐1,3‐dimethyllumazine
Authors: Sato Nobuhiro , Ono Masahiro 
Published: March 2009

AbstractThe titled compound was synthesized by cycloaddition of 5,6,7,8‐tetrahydro‐5,7‐dimethyl‐3,6,8‐trioxo‐3H‐pyrimido[5,4‐c][1,2,5]oxadiazine (1) with 2,3‐dihydrofuran (2a).
Synthesis of heterocycles from molecular nitrogen as a nitrogen source
Authors: Mori Miwako 
Published: March 2009

AbstractNitrogen fixation is a very attractive process. We succeeded in nitrogen fixation using a TiCl4‐ or Ti(O‐i‐Pr)4‐Li‐TMSCl system. Nitrogen fixation proceeds at room temperature under 1 atmosphere pressure of nitrogen to give a mixture of titanium nitride complex 12, titanium nitrogen complex 13, and N(TMS)4. Using the titanium nitrogen complexes 1, various heterocycles were synthesized from the corresponding ketocarbonyl compounds. Nitrogen in air could be fixed using this method. The total syntheses of lycopodine and monomolin I were achieved from nitrogen in air as the nitrogen source. On the other hand, transmetalation of the nitrogen moiety of titanium nitrogen complexes 1 to a palladium complex was realized, and the non‐substituted anilines could be synthesized from ArX and N2 in the presence of the palladium catalyst. Furthermore, amide could be synthesized from ArX, CO, and N2 using the palladium catalyst.
Finding drug candidates in virtual and lost/emerging chemistry
Authors: de Laet Andy , Hehenkamp Jurriaan J. J. , Wife Richard L. 
Published: March 2009

AbstractThere are many opportunities for chemists to help make the drug discovery process more efficient. The virtual world of chemistry contains many challenges to the heterocyclic chemist but this world is very large and attention must be focused on the best candidates for synthesis and testing. The algorithm set SORT&gen makes it possible to form an opinion about the constitution of large compound collections. It also generates the ring scaffolds of the molecules that are missing in these collections. Its application in the drug discovery process is discussed and the smallest missing molecular scaffolds are presented.
2‐Triazolylpyrimido[1,2,3‐cd]purine‐8,10‐diones via 1,3‐dipolar cycloadditions to 2‐ethynylpyrimido[1,2,3‐cd]purine‐8,10‐dione
Authors: Simo Ondrej , Rybár Alfonz , Alföldi Juraj 
Published: March 2009

AbstractThis paper presents the synthesis of a series of 5,6‐dihydro‐4H,8H‐pyrimido[1,2,3‐cd]purine‐8,10(9H)‐dione ring system derivatives with a [1,2,3]triazole ring bonded in position 2. The procedure is based on cycloaddition of substituted alkyl azides to the terminal triple bond of 5,6‐dihydro‐2‐ethynyl‐9‐methyl‐4H,8H‐pyrimido[1,2,3‐cd]purine‐8,10(9H)‐dione (4). This cycloaddition produced two regioisomers −5,6‐dihydro‐9‐methyl‐2‐(1‐substituted‐1H‐[1,2,3]triazol‐5‐yl)‐4H,8H‐pyrimido[1,2,3‐cd]purine‐8,10(9H)‐dione (7) and 2‐(1‐substituted‐1H‐[1,2,3]triazol‐4‐yl) derivative 8. The required 2‐ethynyl deriva tive 4 was obtained from the starting 2‐unsubstituted compound 1 by bromination to yield the 2‐bromo derivative 2, which was converted by Sonogashira reaction to trimethylsilylethyne 3 and finally, the protective trimethylsilyl group was removed by hydrolysis.
A comparative study of the epoxidation of 2‐substituted isoflavones by dimethyldioxirane, sodium hypochlorite, and alkaline hydrogen peroxide (weitz‐scheffer reaction)
Authors: Lévai Albert , Patonay Tamás , Székely Andrea , Vass Erzsébet B. , Adam Waldemar , Jekö József 
Published: March 2009

AbstractThe comparative epoxidation of 2‐substituted isoflavones 9–16 has been conducted by the utilization of three different protocols, viz. epoxidation with isolated dimethyldioxirane (Method A), with sodium hypochlorite (Method B), and with alkaline hydrogen peroxide (Method C), to afford epoxides 17–24. Best results have been obtained with Method C (Weitz‐Scheffer epoxidation). The structures of epoxides have been assigned on the basis of nmr spectral and mass spectral data.
Addition reactions of allyl stannanes to an indolo[2′,3′:3,4]pyrido[1,2‐b]isoquinoline imminium salt
Authors: Unangst Paul C. , Bratton Larry D. , Connor David T. , Roth Bruce D. , Rubin J. Ronald , Trivedi Bharat K. 
Published: March 2009

AbstractThe addition of organometallic reagents to the 13b‐position of the indolo[2′,3′:3,4]pyrido[1,2‐b]isoquinoline imminium salt 4 is described. Reaction of 4 with tetraallyl tin in 2‐methoxyethanol gave the allyl adduct 7 in moderate yield. Further elaboration of 7 yielded the pentacyclic benzylidene alcohols 13 and 14. Structure elucidation of the compounds prepared was achieved by a combination of 1H nmr spec troscopy and X‐ray crystallography.
Synthesis of new tricyclic mesoionic amides via photochemical conversion of a 5‐azido‐1‐mesityl‐3‐phenyltetrazolium salt
Authors: Araki Shuki , Hattori Hiromi , Yamamura Hatsuo , Kawai Masao 
Published: March 2009

AbstractNew mesoionic amides 4 and 5 with novel tricyclic ring systems have been synthesized by the photolysis of a 5‐azido‐1‐mesityl‐3‐phenyltetrazolium salt 1c via the corresponding triplet nitrene inter mediate. The structure of 5 has been determined by X‐ray crystallography.
A kinetic study of the thermolysis of N‐crotyl substituted 1,2,4‐triazoles
Authors: Carlsen Per H. J. , Jørgensen Kåre B. 
Published: March 2009

AbstractA kinetic study of the thermolysis of 4‐crotyl‐3,5‐diphenyl‐4H‐1,2,4‐triazole (1) in a melt of the neat compound was performed at temperatures in the range of 260–350 °C. The main products formed were 1‐crotyl‐3,5‐diphenyl‐1H‐1,2,4‐triazole (3) and 1‐(1‐methylallyl)‐3,5‐diphenyl‐1H‐1,2,4‐triazole (4) together with 3‐methyl‐2,6‐diphenylpyridine (2) and 3,5‐diphenyl‐1,2,4‐triazole (5). Products 2 and 5 were both formed preferentially from 3 and 4. In the melt was observed first order kinetics. Activation parameters for formation of 3 and 4 were determined. Product 3: Ea = 95 kJ/mole. Product 4: Ea= 145 kJ/mole.
New syntheses and spectral properties of pteridine‐related heterocycles from 2,5‐diamino‐3,6‐dicyanopyrazine
Authors: Shirai Kazuko , Fukunishi Koushi , Yanagisawa Atsushi , Takahashi Hiroshi , Matsuoka Masaru 
Published: March 2009

AbstractThe reaction of 2,5‐diamino‐3,6‐dicyanopyrazine (1) as a new pyrazine raw material with alkyl isocyanate in the presence of sodium hydride gave novel heptahydroirnidazo[4,5‐g]pteridine‐2,6,8‐trione (2), but with tertiary butyl isocyanate gave trihydroimidazo[4,5‐b]pyrazine‐2‐ones (3). Similar reaction of 1 with alkyl thioisocyanate followed by alkyl iodide gave tetrahydropyrimido[4,5‐g]pteridines (4). The reac tion of 1 with alkylamine gave the amine‐adduct of the cyano groups which was further reacted with arylaldehyde to give the pyrimido[4,5‐g]pteridine (10). The products prepared are all of interest as potential pesticides and fluorescent chromophores.
1‐(1,2,3‐triazol‐4‐yl)‐benzimidazolones, a new series of heterocyclic derivatives
Authors: Bertelli Lucia , Biagi Giuliana , Calderone Vincenzo , Giorgi Irene , Livi Oreste , Scartoni Valerio , Barili Pier Luigi 
Published: March 2009

AbstractNew 1‐(1,2,3‐triazol‐4‐yl)‐benzimidazolone derivatives were obtained on pursuing research about new tricyclic derivatives of medicinal interest, bearing a 1,2,3‐triazole ring fused with another heterocyclic ring. 1‐[(5‐Carboxamido)‐1,2,3‐triazol‐4‐yl]‐benzimidazolone was prepared by four different chemical routes and it was unequivocally confirmed by spectroscopic methods. Its chemical behaviour, was evaluated by some common chemical reactions such as hydrolysis, esterification, decarboxylation, nitration and N‐methylation.
Synthesis of pyrrolo[3′,4′:2,3]azepino[4,5,6‐cd]indole‐8,10‐diones
Authors: Mahboobi Siavosh , Eluwa Stella , Koller Markus , Popp Alfred , Schollmeyer Dieter 
Published: March 2009

Abstract3‐Amino‐4‐(3‐indolyl)pyrrolin‐2,5‐diones are condensed with various aldehydes and ketones to the cor responding imines. Under Pictet‐Spengler conditions, the latter do not cyclize to pyrrolo‐β‐carbolines, but readily yield pyrrolo[3′,4′:2,3]azepino[4,5,6‐cd]indole‐8,10‐diones.
Haloacetylated enol ethers: 15. Study of the regiochemistry of the cyclo‐condensation of β‐alkoxyvinyl trihalomethyl ketones with N‐methyl thiourea
Authors: Zanatta Nilo , Madruga Claudia Da C. , Marisco Patricia Da C. , Flores Darlene C. , Bonacorso Helio G. , Martins Marcos A. P. 
Published: March 2009

AbstractA study of the regiochemistry of the cyclo‐condensation reaction of ß‐alkoxyvinyl trihalomethyl ketones with an unsymmetric dinucleophile N‐methyl thiourea to afford a series of 1‐methyl‐3‐(4,4,4‐trifluoro[chloro]‐3‐oxo‐1‐butenyl)thioureas and the corresponding N‐methyl pyrimidinethione derivatives is reported. The absolute assignment of the position of the N‐methyl group in the pyrimidine ring was obtained through a nmr study based on two dimensional HMBC and NOESY experiments.
Studies with 1‐functionally substituted alkylbenzotriazoles: An efficient route for the synthesis of 1‐azolylbenzotriazoles, benzotriazolylazines and benzotriazolylazoloazines
Authors: Al‐Omran Fatima 
Published: March 2009

AbstractA new approach to the synthesis of pyrazole, isoxazole, pyridine and pyrazolo[1,5‐α]pyrimidine deriva tives is reported. The structure of the newly synthesized compounds was elucidated by elemental analyses, ir and 1H nmr spectra, and in some cases by 13C nmr investigation.
Synthesis and characterization of new substituted terdentate 2,6‐bis(2′‐quinolinyl)pyridine and 1,3‐bis(2′‐quinolinyl)‐benzene ligands for transition metals
Authors: Mamo Antonino 
Published: March 2009

AbstractA series of N‐N‐N terdendate polypyridine type ligands and their N‐C‐N cyclometalating homologues were synthetized and fully characterized (L1‐L12). Complete assignments of the 1H spectra of the various compounds, accomplished by using a combination of one‐ and two‐dimensional nmr techniques, and 13C data are also reported.
Thermal cyclization of 4‐azido‐3‐nitropyridines to furoxanes
Authors: Stadlbauer Wolfgang , Fiala Werner , Fischer Michaela , Hojas Gerhard 
Published: March 2009

Abstract4‐Chloro‐3‐nitro‐2‐pyridines 3 and 10, obtained from 4‐hydroxy‐2‐pyridones 1 and 8 after nitration and chlorination, gave with sodium azide 4‐azido‐3‐nitropyridines 4 and 11, which cyclized on thermolysis to furoxans 6 and 12. Desoxygenation of the furoxan 6 with triphenylphosphane gave the furazan 7. Thermal decomposition conditions of the azide 4 and the desoxygenation reaction of 6 to 7 were studied by differ ential scanning calorimetry (DSC).
Synthesis of [1,2,5]selena(or thia)diazolo[3,4‐e][1,4]diazepines, [1,2,5]selena(or thia)diazolo[3,4‐e][1,4]oxazepines and [1,2,5]selena(or thia)diazolo[3,4‐c] [1,2,6]thiadiazines
Authors: Ueda Taisei , Doi Wataru , Nagai Shin‐Ichi , Sakakibara Jinsaku 
Published: March 2009

AbstractNovel heterocycles [1,2,5]selenadiazolo[3,4‐e][1,4]diazepines 3a‐c, [1,2,5]thiadiazolo[3,4‐e]‐[1,4]diazepines 7a‐c, [1,2,5]selenadiazolo[3,4‐e][1,4]oxaepines 4a,b, [1,2,5]thiadiazolo[3,4‐e]‐[1,4]oxazepines 9a‐c and [1,2,5]selena(or thia)diazolo[3,4‐c][1,2,6]thiadiazines 10a,b were synthesized starting form 4,6‐dimethyl[1,2,5]se]enadiazolo[3,4‐d]pyrimidine‐5,7(4H,6H)‐dione 1 or 4,6‐dimethyl‐[1,2,5]thiadiazolo[3,4‐d]pyrimidine‐5,7(4H,6H)‐dione 5.
Synthesis and properties of some 2,3‐disubstituted 6‐fluoro‐7‐(4‐methyl‐1‐piperazinyl)quinoxalines
Authors: Abdel‐Jalil Raid J. , Al‐Qawasmeh Raed A. , Voelter Wolfgang , Heeg Peter , El‐Abadelah Mustafa M. , Sabri Salim S. 
Published: March 2009

AbstractThe 2,3‐disubstituted 6‐fluoro‐7‐(4‐methyl‐1‐piperazinyl)‐quinoxalines (3–11) were synthesized for bioassay via reaction of 1.2‐diamino‐4‐fluoro‐5‐(4‐methyl‐1‐piperazinyl)benzene (2) with the appropriate 1,2‐dicarbonyl compounds. However, none of the tested compounds 3–11 showed significant in vitro activ ity against E. coli ATCC11229, S. aureus ATCC6538 and C.albicans SATCC10231.
Synthesis of indole‐4‐carboxaldehydes and 4‐acetylindole from N‐alkyl‐5‐aminoisoquinolinium salts
Authors: Muchowski Joseph M. 
Published: March 2009

AbstractN‐Alkyl‐5‐aminoisoquinolinium salts (8a‐d) are converted into indole‐4‐carboxaldehydes (1a‐c) on heating in a two phase alkyl acetate‐water system containing an excess of a 2:1 sodium bisulfite‐sodium sulfite mixture. 4‐Acetylindole 1e is prepared in the same way from 1‐methyl‐2‐cyanomethylisoquinolinium bromide 8f.
Nucleophilic addition to 3‐methyl‐1‐(4‐nitrophenyl)‐2‐phenyl‐4,5‐dihydroimidazolium iodide
Authors: Xia Chizhong , Tang Yiqing , Zhou Peiwen 
Published: March 2009

AbstractReactions of the 1,2‐diaryl 4,5‐dihydroimidazolium, represented by 3‐methyl‐1‐(4‐nitrophenyl)‐2‐phenyl‐4,5‐dihydroimidazolium iodide 1, with ethylenediamine afforded a benzylidyne unit transferred product, 2‐phenyl‐2‐imidazoline 2; a ring‐opened adduct 4 was produced when excess ethylenediamine was used. Reactions of 1 with hydroxylamine, malononitrile, and nitromethane anions produced ring‐opened products, 5, 7, and 8 respectively.
Preparation and structure elucidation of 1,6,9,13‐tetraoxadispiro(4.2.4.2)tetradecane
Authors: Gaede Bruce , Henry Rodger , Chamberlin Steven A. 
Published: March 2009

AbstractThe tricyclic title compound, a symmetrical dispiro oxygen heterocycle, was isolated as a byproduct in the hydrogenation of furfuryl alcohol in the presence of hydrochloric acid. NMR studies and single crystal X‐ray analysis have established the relative stereochemistry of the two ketal carbons. Formation of the observed trans stereoisomer under equilibrating conditions is attributed to the anomeric effect.
Lariat ether alcohols based on dibenzo‐16‐crown‐5
Authors: Bartsch Richard A. , Bitalac Leah P. , Cowey Charles L. , Elshani Sadik , Goo Mi‐Ja , Huber Vincent J. , Ivy Sheryl N. , Jang Youngchan , Johnson Russell J. , Kim Jong Seung , Luboch Elzbieta , Mcdonough Joseph A. , Pugia Michael J. , Son Byungki , Zhao Qiang 
Published: March 2009

AbstractSynthetic routes to forty‐four dibenzocrown ether alcohols are reported. The new crown ether com pounds are based on a sym‐dibenzo‐16‐crown‐5 platform. Most have a hydroxy group and an alkyl, aryl, aralkyl, alkenyl, alkynyl, or perfluoroalkyl group on the central carbon of the three‐carbon bridge. Others have substituted benzene rings and either a hydroxy or ‐O(CH2)nOH group attached to the central carbon of the three‐carbon bridge.
Ring opening of cyclic ethers by sulfuric acid ‐ acetic anhydride
Authors: Tanoue Yasuhiro , Hamada Moritsugu , Kai Norihisa , Nagai Takeshi , Sakata Kazunori , Hashimoto Mamoru , Morishita Shin‐Ichi 
Published: March 2009

AbstractCyclic ethers such as tetrahydrofuran or tetrahydropyran were easily cleaved at room temperature by sulfuric acid ‐ acetic anhydride providing the corresponding diacetoxyalkanes in good yield. The ring opening was applicable to saturated cyclic ethers, regardless of the presence of substituent groups.
Synthesis of novel spiroazetidinones by selective lactam‐carbonyl cleavage in 1‐aryl/cyclohexyl‐3,3‐diphenyl‐1′‐(diphenylacetyl)spiro[azetidin‐2,3′‐indoline]‐2′,4‐diones
Authors: Singh Girija S. 
Published: March 2009

AbstractTitled compounds undergo selective N‐C cleavage on treatment with sodium hydroxide in ethanol affording a series of novel isatin‐based spiroazetidinones.
The synthesis and crystal structure of 2,6,9‐trimethyl‐4,8‐dinitro‐2,6,9‐triazabicyclo[3.3.1]nona‐3,7‐diene
Authors: Ostercamp Daryl L. , Wiles Sarah 
Published: March 2009

AbstractThe first preparation of title compound 1 is accomplished. Its heterocyclic structure was characterized spectroscopically and by X‐ray structure analysis.
A facile synthesis of 3‐Substituted 5‐Oxo‐1,2,4‐thiadiazoles from amidoximes
Authors: Kohara Yasuhisa , Kubo Keiji , Imamiya Eiko , Naka Takehiko 
Published: March 2009

AbstractThe reaction of amidoximes 1 with 1,1′‐thiocarbonyldiimidazole (TCDI) followed by treatment with silica gel or boron trifluoride diethyl etherate (BF3·OEt2) provided 3‐substituted 4,5‐dihydro‐5‐oxo‐1,2,4‐thiadiazoles 2 in moderate yields. The Lewis acids are considered to promote the rearrangement of the thioxocarbamate intermediates 5 to the thiol carbarn ate intermediates 7, which cyclize to afford 4,5‐dihydro‐5‐oxo‐1,2,4‐thiadiazoles 2.
Synthesis of 1‐[(pyrazol‐3‐yl)methyl]pyridazin‐6‐ones
Authors: Chung Hyun‐A , Kang Young‐Jin , Kweon D. H. , Lee Woo Song , Yoon Yong‐Jin 
Published: March 2009

AbstractThis paper presents the synthesis of 1‐[(pyrazol‐3‐yl)methyl]pyridazin‐6‐ones from ethyl 4‐(4,5‐dichloro‐6‐oxopyridazin‐1‐yl)‐3‐oxobutanoate.