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1.
Reduction of 5-benzoyl-8-methyl-2-oxo-3,4,4a,5,6,7-hexahydro-2H-pyrano[3,2-b] pyridine () with lithium aluminium hydride afforded (1R*,5S*,6R*,9S*)-2-benzyl-5-methyl-2-azabicyclo[3.3.1]nonane-6,9-diol (). 相似文献
2.
(+/-)-6,9α-Methanoprostaglandin I3, () and (+/-)-5,6-dihydro-6,9α-methano-6β-prostaglandin I3, () have been synthesized using a new method for the stereoselective introduction of the 15α-hydroxy group via a stereoselective electrophilic addition of phenyl-sulfenyl chloride to the enol ether () and () respectively. 相似文献
3.
Syntheses for pyrazolo[3,4-g]quinazolin-8(7H)-one () and its [3,4-h]-analog 11 have been developed involving elaboration of aminoindazolcarboxylic acids and from correspondingly substituted methylnitroindazols, and subsequent anellation of the pyrimidine ring by v. Niementowski cyclization. 相似文献
4.
The first syntheses of [1.1.1.1.1]paracyclophane () and [1.1.1.1.1.1]paracyclophane () are described, featuring a trifluoroacetic acid promoted Friedel-Crafts cycloalkylation as the final step. 相似文献
5.
Ernst-Ulrich Würthwein Jayaraman Chandrasekhar Eluvathingal D Jenmis Paul von Ragué Schleyer 《Tetrahedron letters》1981,22(9):843-846
Semi-empirical (MINDO/3 and UNDO) MO calculations on highly strained planar tetracoordinate carbon candidates indicate the central carbons in - [4.4.4.4] fenestrane () to have pyramidal () and in trans-[4.4.4.]fenestrane () to have distorted tetrahedral () geometries. In [2.2.2.2]paddlane (), the two central carbons are pentacoordinate. Each is nearly coplanar with four carbon neighbours; additionally, the two bridgehead carbons are connected by a single bond (). 相似文献
6.
The 185-nm denitrogenation of 2,3-diazabicyclo[2.2.1]heptene () afforded bicyclo[2.1.0]-pentane () and cyclopentene () presumably via a “hot” cyclopentane-1,3-diyl diradical (); 1,4-pentadiene () and methylenecyclobutane () were secondary products of the 185-nm photolysis of () and (). 相似文献
7.
Mikio Hori Kiyomi Tanaka Tadashi Kataoka Hiroshi Shimizu Eiji Imai Kazuhiko Kimura Yoshinobu Hashimoto 《Tetrahedron letters》1985,26(10):1321-1322
5,7-Dimethyl[1,2,4]triazolo[1,5-a]pyrimidinio-3-phenacylide () generated by the reaction of an iminium salt () with 1 eq. of triethylamine, underwent a new thermal ring cleavage of the triazole moiety to give the pyrimidine derivative. However reaction of with 2 eq. of triethylamine afforded the 2-iminooxazoline derivative. The iminooxazoline reacted with nucleophiles such as alcohols or amines to give imidazoles. 相似文献
8.
L.A.M. Turkenburg P.M.L. Blok W.H. de Wolf F. Bickelhaupt 《Tetrahedron letters》1981,22(34):3317-3320
Base induced elimination of HCl from the dichloro[5.3.1]propellane gives a mixture of [5]metacyclophane () and tetrahydrocyclopentacyclooctenes (), while the stereoisomeric affords quantitatively. 相似文献
9.
Reaction of nerol () with thallium(III) perchlorate gave 6-oxabicyclo[3.2.1]octane derivatives () and (), and 6,9-dioxabicyclo[3.3.1]nonane derivatives () as the cyclization products. 相似文献
10.
The chemistry of phenalenium systems XXXIII. The Dibenzo[de;thi]naphthacenyl dication and the dianon
The dibenzo[de;hi]naphthacenyl dication () and dianion () have been generated from a mixture of the corresponding precursor hydrocarbons. The pmr spectra of and indicated that the positive and the negative charges were found to be fully delocalized over the molecules, respectively, consistent with the C2v-symmetry structures. The pmr chemical shifts of correlate well with the Hückel charge densities. 相似文献
11.
The photochemical reactions of tetracyclic azo compounds () giving and via diazoethane derivatives () were investigated in addition to the nitrogen extrusion reactions leading to tetracyclo[4.3.0.02,9.05,7nonenes (). 相似文献
12.
H.R. Buser P.M. Guerin M. Tóth G. Szöcs A. Schmid W. Francke H. Arna 《Tetrahedron letters》1985,26(4):403-406
(Z,Z)-6,9-Nonadecadien-3-one and (Z,Z,Z)-3,6,9-nonadecatriene were identified by GC-EAD and GC-MS in ovipositor extracts of . ; the synthetic mixture is attractive to males of the species in the field. 相似文献
13.
Yoshito Tobe Yasuyoshi Ueda Masaharu Matsumoto Yasuo Sakai Yoshinobu Odaira 《Tetrahedron letters》1982,23(5):537-538
Bicyclo[6.2.2]dodecadienes (), (), and () having two bridgehead double bonds were synthesized by the pyrolysis of the acetate (). 相似文献
14.
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
15.
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
16.
A short route to the 2-azabicyclo[3.3.1]nonan-7-one system is described. Condensation of 4-piperidones with diethyl 2-oxopropylphosphonate, followed by catalytic hydrogenation furnished the corresponding piperidylpropanones which were cyclized with mercuric acetate in acetic acid to the target target bicyclic ketones . The Fischer indole synthesis from afforded regioselectively the indole [3,2-f]morphan , a new heteromorphan type. 相似文献
17.
G. Eulenberger 《Journal of solid state chemistry》1984,55(3):306-313
The new compound Tl6[Ge2Te6] was prepared by thermal synthesis from the elements. The material is triclinic, space group , with a = 9.471(2), b = 9.714(2), c = 10.389(2) Å, α = 89.39(1), β = 97.27(1), γ = 100.79(1)°, and Z = 2. The crystal structure was determined from single-crystal intensity data measured by means of an automated four-circle diffractometer and refined to an R value of 0.053 for 1831 observed reflections. Tl6[Ge2Te6] is characterized by Ge2Te6 units with GeGe bonds which are linked into a three-dimensional structure by Tl atoms coordinated to essentially six Te atoms. The most important mean distances are Å, Å, and Å. The lone 6s electron pairs of the thallium(I) atoms exhibit significant stereochemical activity. Tl6[Ge2Te6] represents a new structure type. 相似文献
18.
Photochemical cycloaddition of cyclopentene with enone esters containing different chiral auxiliaries yielded anti and syn adducts and in good yield and with moderate to high (79%) enantiomeric excesses. 相似文献
19.
A.D. de Wit W.P. Trompenaars D.N. Reinhoudt S. Harkema G.J. van Hummel 《Tetrahedron letters》1980,21(18):1779-1780
3-Nitrobenzo[b]furan and 1-diethylaminopropyne react thermally at 5–10°C to give a 1:1 addition product () in which one of the oxygen atoms of the nitro group is transferred to C-1 of the acetylene. The structure of the benzofuro[3,2-c]isoxazole () has been determined by X-ray crystallography. 相似文献
20.
Theodorus A Van Der Knaap Theodorus C Klebach Foppe Visser Rimmer Lourens Friedrich Bickelhaupt 《Tetrahedron》1984,40(6):991-997
Cycloaddition reactions of mesityl(diphenyliiifithylene)phosphine () were Investigated. With several dienes, no Diels-Alder reactions were oEserved. With azides, diphenyidiazomethane and 2,4,6-trimethylbenzonitrile oxide, the corresponding cycloadducts (were obtained. In the case of phenyl azide, a competing Staudinger reaction occurred leading to . 相似文献