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1.
Minoru Isobe Supaporn NiyomchonChia-Yi Cheng Anuch Hasakunpaisarn 《Tetrahedron letters》2011,52(16):1847-1850
A sesterterpenoid solanoeclepin A (1) has a unique structure including a bicyclo[4.2.0]octane substructure, for which a new synthetic methodology is explored particularly to cyclize functionalized cyclobutane rings. An optically active (R)-carvone and a racemic cyclohexenone were each converted into the respective epoxyvinylsulfones, and then subjected to the heteroatom-directed conjugate addition (HADCA) by a lithium acetylide nucleophile. The intermediate carbanions from HADCA were used for the following epoxide opening reaction yielding the four-membered carbocyclic products. 相似文献
2.
[structure: see text]. We report a new methodology for the construction of novel and uniquely shaped 3-azabicyclo[4.2.0]octan-4-one derivatives by combining the Ugi multicomponent reaction with [2+2] enone-olefin photochemical transformations. The overall sequence is capable of creating up to five stereocenters; however, in most cases, only two diastereomers are observed. 相似文献
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A structural analog of morphinan- 2,3-dimethyl-6,7-benzo-5,9-(1,2-indano)-2-azabicyclo-[3.3.1]non-6-ene -was synthesized from 3-methyl-2-azafluorene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1671–1672, December, 1972. 相似文献
6.
Reaction of lithium enolates of simple ketones with (+/-)-phenyl vinyl sulfoxide has potential for the convergent construction of complex fused ring systems containing a bicyclo[n.2.0]alkan-1-ol. The formation of sulfinylbicyclo[4.2.0]octan-1-ols 1-3 from the lithium enolate of cyclohexanone with (+/-)-phenyl vinyl sulfoxide or (R)-(+)-p-tolyl vinyl sulfoxide 18 was used to probe the mode of this novel cyclization reaction. Using phenyl vinyl sulfoxide, variations in the reaction lighting and solvent were investigated, in conjunction with radical trapping (TEMPO) and isotope labeling (deuterium) experiments. Cyclization to form sulfinylbicyclooctanols 1-3 is likely to proceed via an intermediate that ring closes to the bicycloalkanol anion 11 and was presently favored by the use of solvents such as THF or DME. 相似文献
7.
The titled annulenone 6, the first benz-annelated 11-membered fully conjugated ketone, has been prepared by the aldol type condensation of 3-benzoxepin-2,4-dialdehyde 3 and dimethyl acetone-dicarboxylate. Some evidence for the nonaromatic character of 6 could be obtained from the NMR and IR spectra as well as protonation behaviour of 6.The NMR spectrum of 6 in conc H2SO4 confirmed the presence of an aromatic 1-hydroxy-6,7-benzo-4,9-oxido[11]annulenyl cation 7. 6,7-Benzo-4,9-oxido-1-hydroxy-1-homo[10]annulene 11 was prepared by the NaBH4 reduction of 6. The treatment of 11 with CF3COOH regenerated another completely delocalized [11]annulenyl cation 12. The pkR+ of 12 was obtained as ?4·1, spectrophotometrically. The electronic spectra of these novel cations (7 and 12) were found to be similar to those of 4,5-(2′,3′-naphtho)tropylium cations (13a and 13b), respectively. 相似文献
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Masahiko Okada Hiroshi Sumitomo Hiroto Mori H. K. Hall Ray J. H. Chan M. Bruck 《Journal of polymer science. Part A, Polymer chemistry》1990,28(12):3251-3260
A novel bicyclic oxalactam 2-oxa-5-azabicyclo [2.2.21 octan-6-one (2,5-BOL) was synthesized from sodium 3,4-dihydro-2H-pyran-2-carboxylate through a seven-step reaction sequence. Anionic ring-opening polymerization of 2,5-BOL was carried out in bulk at 12OOC or in dimethyl sulfoxide at 40, 60, and 80°C by using potassium pyrrolidonate and the N-benzoyl derivative of 2,5-BOL as catalyst and activator, respectively. The polymerization gave a new polyamide containing cis- and trans-2,5-linked tetrahydropyran rings in the main chain. The cis/trans ratio varied from 70/30 to 95 /5 depending on the reaction conditions. The polyamide having number average molecular weights of 3000–8000 was soluble in a variety of solvents including methanol, ethanol, dimethyl sulfoxide, dimethylformamide, chloroform, and dichloromethane. It began to decompose at 280–32OOC depending on the compositions of the cis- and trans-2,5-linked structural units. The anionic ring-opening polymerizability of 2,5-BOL was found to be much lower than its structural isomer, 8-oxa-6-azabicyclo[ 3.2.11 octan-7-one (8,6-BOL). 相似文献
10.
An efficient synthesis of the 2-azabicyclo[2.1.1]hexane ring system has been accomplished starting from cis-cyclobut-3-ene-1,2-dicarboxylic anhydride 7, which was prepared using a photochemical method. The key step of this new strategy involved a stereoselective electrophilic addition of phenylselenyl bromide to the double bond of cyclobutene dicarbamate 16 derived from 7. The subsequent ring closure of 17a in the presence of sodium hydride afforded the 2-azabicyclohexane compound 18 with a satisfying overall yield. Reductive removal of the phenylselenyl group and subsequent deprotection led rapidly to the amino derivative 4a functionalized on the carbon ring. Syntheses of the hydroxy and carboxylic derivatives 4b,c were then achieved from the intermediary disulfonamide 23. Displacement of the activated amino group by potassium acetate yielded hydroxy derivative 4b after three additional steps. Finally, oxidation of the alcohol function of 4b under Jones conditions followed by hydrogenolysis afforded the carboxylic derivative 4c, which is the first reported beta-isomer of 2,4-methanoproline 1. 相似文献
11.
Heinrich Berger Werner Seebacher Marcel Kaiser Reto Brun Robert Saf Robert Weis 《Monatshefte für Chemie / Chemical Monthly》2009,140(5):495-502
Abstract Several 4-amino-6,7-diarylbicyclo[2.2.2]octan-2-ols bearing varying substituents on the aromatic rings were synthesized following
a manual method for applying the Hansch approach. All new compounds were tested for their activity against the causative organisms
of East African sleeping sickness and malaria tropica. Structure activity relationships are discussed.
Graphical abstract
相似文献
12.
Heinrich Berger Werner Seebacher Marcel Kaiser Reto Brun Robert Saf Robert Weis 《Monatshefte für Chemie / Chemical Monthly》2009,31(6):495-502
Abstract
Several 4-amino-6,7-diarylbicyclo[2.2.2]octan-2-ols bearing varying substituents on the aromatic rings were synthesized following a manual method for applying the Hansch approach. All new compounds were tested for their activity against the causative organisms of East African sleeping sickness and malaria tropica. Structure activity relationships are discussed. 相似文献13.
Reaction of 1,2,3,4-tetrahydroquinoline (1) with different α,β-unsaturated acids in the presence of PPA has been investigated. With acrylic acid, 1 affords two compounds identified as 1-keto-benzo[i,j]quinolizine (III) and 2,3,5,6,7,9,10,1 1-octahy dro-1H-cy el open ta [9,10] benzo [i,j]-quinolizine-1,9-dione (IV). A similar reaction of 1 with a-methyl acrylic and crotonie acids gives compounds V and VI whose structures are analogous to that of IV. These were deduced from their spectral and analytical data. 相似文献
14.
The hetero-Diels-Alder reaction of an electron-deficient nitrile, p-toluenesulfonyl cyanide, with the silyl enol ether of cyclohexenone produced a hydrolytically sensitive [4 + 2] adduct in good yield. Use of Mander's reagent, ethyl cyanoformate, with the same diene, produced an unstable adduct. Hydrolysis of the tosyl cyanide adduct resulted in the isoquinuclidinone 2-aza[2.2.2]octa-3,5-dione as a crystalline compound in excellent yield from the nitrile. 相似文献
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Kenichi Somekawa Yasuo Okumura Kunitomi Uchida Tetsuro Shimo 《Journal of heterocyclic chemistry》1988,25(3):731-734
The low temperature photoaddition of 2-pyridone with dimethyl acetylenedicarboxylate gave a [4 + 2]-cycloadduct and a [2 + 2]-cycloadduct across the 5,6-position of 2-pyridone. Their formations were competing with a Michael reaction of the two substrates at the room temperature reaction. The reactions of other pyridones with dimethyl acetylenedicarboxylate gave [2 + 2]- and/or [4 + 2]-cycloadducts. The [2 + 2]-cycloadducts underwent an intriguing rearrangement to fused β-lactams. 相似文献
18.
Abbas Shafiee 《Journal of heterocyclic chemistry》1976,13(2):301-304
A method was developed for the synthesis of 5-carbethoxy-4-formyl-1,2,3-thiadiazole (I), its isomer (II); 5-benzoyl-4-formyl-1,2,3-thiadiazole (III), and its isomer (IV). It was demonstrated that although compounds I, III and IV with hydrazine gave 7H-1,2,3-thiadiazolo[4,5-d]-pyridazin-7-one (XXII), 7-phenyl-1,2,3-thiadiazolo[4,5-d]pyridazine (XXIII) and 4-phenyl-1,2,3-thiadiazolo[4,5-d]pyridazine (XXV), respectively; however, compound I gave its corresponding hydrazone (XXIV). 相似文献
19.
Akira Tanaka Kenichi Yakushijin Shigetaka Yoshina 《Journal of heterocyclic chemistry》1977,14(6):975-979
4H-Furo[3,2-b]indole (III) was prepared from deoxygenation of 2-(2-nitrophenyl)furan (II) with triethyl phosphite and thermolysis of 2-(2-azidophenyl)furan (VI). 4H- or 4-alkylfuro [3,2-b]indole-2-carboxaldehydes (VIII, IXa-c) were obtained by Vilsmeier formylation of the corresponding furo[3,2-b]indoles (III, VIIa-c). 4H-Furo[3,2-b]indole-2-carboxaldehyde (VIII) was submitted to the Cannizzaro, Wittig and reduction reactions. The Shiff's bases were obtained by the reaction of 4-ethylfuro[3,2-b]indole-2-carboxaldehyde (IXb) with amines. J. Heterocyclic Chem., 14, 975 (1977) 相似文献
20.
Dinsmore CJ Bergman JM Bogusky MJ Culberson JC Hamilton KA Graham SL 《Organic letters》2001,3(6):865-868
A new synthesis of the 3,8-diazabicyclo[3.2.1]octan-2-one framework is described. Transannular enolate alkylation of piperazinone derivatives provides a flexible route to highly constrained bicyclic peptidomimetic synthons with substitution at the Calpha position. The chemistry was used to produce a conformationally constrained farnesyltransferase inhibitor, which aided the elucidation of enzyme-bound conformation. 相似文献