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1.
(1R,5S)-2S-Deuteriobicyclo[3.2.1]octan-3-one () and (1R,5S)-2R-Deuteriobicyclo[3.2.1]octan-3-one (), prepared by diazomethane ring enlargement of (1S,4R)-2(exo)-deuteriobicyclo-[2.2.1] heptan-2-one and (1S,4R)-2(endo)-deuteriobicyclo[2.2.1]heptan-2-one respectively, both gave (?) n-π* circular dichroism (CD) Cotton effects, Δεmax294 = ?0.05 and Δεmax294=?0.1, respectively, in hydrocarbon solvent. (1S,5R)-2S-Deuterio-6,6-diaethylbicyclo[3.1.1] heptan-3-one () and (1S,5R)-2R-deuterio-6,6-dimethylbicyclo[3.1.1] heptan-3-one (), prepared from (-) myrtenal, both exhibited extraordinary vibrational fine structure for the n-π* CD transitions observed in hydrocarbon solvent and oppositely?signed CEs, Δεmax282=?0.01 and Δεmax279=+0.01 respectively in CF3CH2OH solvent. 相似文献
2.
The acid catalysed reaction of 4-oxa-homoadamantan-5-one () with benzene yielded a mixture of 4a-phenyladamantan-2-one (), the equatorial isomer' () and 2-phenyl-2,4-o- benzenoadamantane () A plausible reaction pathway for the occurrence of . is put forward. The structure of , was deduced from spectroscopic data and reaction of the proposed intermediate 2,4a-diphenyladamantan-2-ol () with acid. 2,4-o-Ben-zenoadamantane () is prepared likewise. 相似文献
3.
Ratna Dasgupta Pranab R. Kanjilal Swapan K. Patra Manish Sarkar Usha Ranjan Ghatak 《Tetrahedron》1985,41(23):5619-5625
The efficacy of a new acid-catalyzed intramolecular C-alkylation has been demonstrated by the synthesis of 1-methyl-4--methoxyphenylbicyclo [2.2.2] octan-2-one () and 4--methoxyphenylbicyclo [2.2.2] octan-2-one () from easily accessible starting materials. The carbinol , derived from , undergoes facile rearrangement leading to 1--methoxyphenyl-4-methyl bicyclo [3.2.1] oct-3-ene (), which has been transformed to -1--methoxyphenyl-4-methylbicyclo [3.2.1] octan-3-one (). 相似文献
4.
E.G. Frandsen 《Tetrahedron》1977,33(8):869-873
The reaction of 4- and 5-aryl-3-methylthio-1,2-dithiolylium iodides with 4-hydroxy-6-methyl-2-pyran-2-one and 4-hydroxycoumarin has been studied. 4-Substituted salts yielded 3-aryl-7-methyl-2-thioxo-2,5-pyrano [3,2-c]pyran-5-ones and 3-aryl-2-thioxo-2H,5H-pyrano[3,2-c]benzo[e]pyran-5-ones, respectively, whereas 5-substituted salts gave rise to 3-(5′-aryl-1′,2′-dithiol-3′-ylidene)-6-methyl-2-pyran-2,4-diones and 3-(5′-aryl-1′,2′-dithiol-3′-ylidene)-2-benzo [b]-pyran-2,4-diones. 相似文献
5.
David A. Lightner Chwang Siek Pak B.Vincent Crist Stephen L. Rodgers John W. Givens 《Tetrahedron》1985,41(19):4321-4330
(lS,5S)-exo-2(R)-Methylbicyclo[3.1.0]hexan-3-one () and (lS,5S)-endo-2(S)-methylbicyclo[3.1.0]hexan-3-one (2) were synthesized and their circular dichroism (CD) spectra run. Conformational analysis based on molecular mechanics calculations and Karplus equation analyses of vicinal H¦H NMR coupling constants indicate boat-like sofa conformations for both and , with very little ring distortion from the symmetry of the parent bicyclo[3.1.0]hexan-3-one. The lone dissymmetric ψ-axial and ψ-equatorial methyl groups of and , respectively, are both octant consignate. The natural product analogs of and , (?)-3-isothujone () and (+)-3-thujone () were prepared and examined similarly. Their α-methyl perturbers dominate the CD n-π★ Cotton effects. 相似文献
6.
Two-step synthesis of 1,2-dihydrocyclobuta[]isoquinolin-4(3H)-ones, novel cyclobutane-fused heterocycles, from 3-methoxy-2-methylisoquinolin-1(2H)-one and their reacion with olefins are described. 相似文献
7.
Suzanne Butt H.Geoff Davies Michael J. Dawson Gordon C. Lawrence Jeff Leaver Stanley M. Roberts Michael K. Turner Basil J. Wakefield Wilfred F. Wall John A. Winders 《Tetrahedron letters》1985,26(41):5077-5080
Bicyclo[3.2.0]hept-2-en-6-one (1) was reduced with an alcohol dehydrogenase from and a whole cell system () with excellent substrate enantioselectivity: 7,7-dimethylbicyclo[3.2.0]hept-2-en-6-one (2) was similarly reduced using the 3α,20β-hydroxysteroid dehydrogenase from Streptomyces while furnished both 6S-alcohols (4a), (6b) with high optical purity. 相似文献
8.
Merle A Battiste Donna.D McRitchie Paul G Gassman William F Reuss Jonathan N Chasman John Haywood-Farmer 《Tetrahedron letters》1979,20(23):2097-2100
Methyl substituent probes at the C-2 and C-2,C-4 positions of -tricyclo[3.2.1.02,4] octan-8-one() have provided kinetic evidence confirming the simultaneity of C-2,C-4 cyclopropane bond cleavage in the rate-determining step for thermal extrusion of carbon monoxide. 相似文献
9.
A. Corsico Coda G. Desimoni M. Pappalardo P.P. Righetti P.F. Seneci G. Tacconi R. Obberti 《Tetrahedron》1985,41(12):2545-2555
The copper(II) acetate complex of isatin-3-phenylhy-drazone (2a) reacted with dimethyl acetylenedicarboxylate (DMAD) by two competitive pathways: a Cu++ oxidation of the ligand and a [2+2] cycloaddition. The former reaction gave 3-car- benindolin-2-one (13) which reacted with DMAD in a l,3-dipolar cycloaddition, to give 3a. This was synthesized by an independent route. The phenyl radical, generated in the same process, was trapped by three DMAD and gave . The [2+2] cycloaddition gave a spiro adduct 10 which, by electrocyclic ring opening and intramolecular cyclization, allowed isolation of a pyridazino [3,4-b] indole (|5a). The reaction was performed on -chlorophe-nylhydrazone 1b and the structure of 5b was demonstrated by X-ray analysis. A rationalization of the reactivity was attempted in terms of MO interactions of the reactants. 相似文献
10.
The extraction of Co(II) with mixtures of 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one ((H)PMBP) and tri-n-octylamine (TOA) is investigated in order to explore the influence of diluents and inorganic anions with synergistic acidic extractant + liquid anion exchanger systems. Although it is proved that the same species [HTOA]+ [Co(PMBP)3]? is extracted from various inorganic media, with toluene as the diluent, the presence of ClO4? SO42? or Cl? anion modifies the distribution of the anions which are associated to (HTOA)+ in the organic phase, leading to different synergistic equilibria; with Cl? or SO42?: + ,PMBP?) ?,Co(PMBP)3? (log K = 6.10) and with ClO4? : + + ,ClO4? ? ,Co(PMBP)3? + H+ + ClO4? (log K = 2.34) The same synergistic equilibrium is observed for the extraction of Ni(II) from ClO4? medium, with a comparable value of the constant (log K = 2.45). The synergistic effect is cancelled in n-octanol. 相似文献
11.
Maria Luisa Gelmi Donato Pccar Pasqualina Trimarco Mariella Valsecchi Riccakdo Destro Marzia Ballabio 《Tetrahedron》1984,40(20):4025-4032
1R*, 4R*, 5S*, 5'S*-5'-Amino-1'-(4-nitrophenyl)-4',5'-dihydrospiro[bicyclo [2.2. 1]hept-2-ene[5.4]-1',2',3'-triazoles] have been obtained both by ?4 +2]-cycloaddition of cyclopentadiene to amino-methylene-1-(4-nitrophenyl)-4,5-dihydro-v-triazoles and by [3+2]-cycloaddition of 4-nitrophenylazide to 5-aminomethylene-2-norborenes . The configuration has been fully established by X-ray crystallographic analysis. The course of the cycloaddition and the thermal behaviour of are discussed. 相似文献
12.
Curt Wentrup Edeline Wentrup-Byrne Paul Müller Jürgen Becker 《Tetrahedron letters》1979,20(44):4249-4252
2-Ethynylidene is obtained by flash vacuum pyrolysis of naphtho[b] cyclopropene and 4-(2-indenylmethylidene)-3-methylisoxazol-5-(4)-one. 相似文献
13.
3,3-Dichlorotricyclo[5.1.0.01,4]oct-5-en-2-one () was prepared by addition of dichloroketene to 1,3-cyclohexadiene followed by allylic bromination and dehydrobromination. 相似文献
14.
《Tetrahedron》1987,43(13):3021-3030
A new synthesis of 9,10-dimethoxy-1,3,4,6,7,11b-hexahydro-2H-benzo aquinolizin-2-one ( and its 3-ethyl derivative via the corresponding 2-(3,4-dimethoxyphenyl)-4-piperidone ethylene acetals is reported. Alkylation of 2-arylpipendires with 2-bromoethanol followed by oxidation of the resulting amino alcohols with oxalyl chloride and dimethyl sulfoxide afforded the aldehydes , which were cyclized with hydrochloric acid to give 7-hydroxybenzo[α]quinolizidines . The reduction of with trinethylsilane and subsequent acid hydrolysis led to benzo aquinolizidin-2-ones . 相似文献
15.
16.
The 1H and 13C nmr spectra of , -9-oxobicyclo[3.3.1]nonane-2,4-dicarboxylic acid, 3, in DMSO-d6 or alkaline D2O, clearly show that it exists in a --conformation with carboxyl groups, thus being the first case of - preference of a bicyclo[3.3.1] nonan-9-one due to the presence of ,-2,4- substituents. 相似文献
17.
Two novel nucleosides, mycalisines A and B, have been isolated from a marine sponge and their structures elucidated as 4-amino-5-cyano-7-(3--methyl-5-deoxy-β-D--pent-4-enofuranosyl)-pyrrolo[2,3-]pyrimidine and 5-cyano-7-(3--methyl-5-deoxy-β-D--pent-4-enofuranosyl)-pyrrolo[2,3-]pyrimidine-4-one, respectively. Both compounds inhibit cell division of fertilized starfish eggs. 相似文献
18.
The thermal rearrangement of 2,4-di(N-aryl)amino-1,3,5-triazin-6yl-prop-2-ynyl ethers yield a mixture of 6-methyleneimidazo(1,2-a)-1,3,5-triazine-4-one and 6-methylimidazo(1,2-a)-1,3,5-triazine-4-one , whereas under the influence of mercuric trifluroacetate the ethers yield only , at room temperature. Mechanisms invoking [3,3] sigmatropic rearrangement of ethers were proposed to account for the product formation. 相似文献
19.
Refluxing the oximes () of naphtho-[1,8-bc] pyran-3(2H)-one and () of 3 (2H)-benzofuranone with alcoholic hydrogen chloride give the corresponding α-alkoxy-ketones , , and α-chloroketone respectively. This transformation appears to be related to the acid conversion of N-aryhydroxylamines to o. and p. substituted anilines (BAMBERGER réarrangement. 相似文献
20.
A novel synthesis of the iridoids (±)-isoiridomyrmecin and (±verbenalol is described starting from the tricyclo |3.3.0.02,8|octan-3-one using cis fused bicyclo |3.3.0|octenes as intermediates. The heterocyclic ring of the iridoids was formed in the final stages of the syntheses. 相似文献