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1.
Géza Stájer Angela E. Szabó Ferenc Fülöp Gábor Bernáth Pál Sohár 《Journal of heterocyclic chemistry》1984,21(5):1373-1376
3-exo-Aminobicyclo[2.2.1]hept-5-ene-2-exo-carboxylic acid and ethyl 3-endo-aminobicyclo[2.2.1]heptane-2-endo-carboxylate ( 6 ) were reduced with lithium aluminum hydride to the corresponding bicyclic aminoalcohols 3 and 4 . These and the saturated endo-endo and exo-exo N-methylaminoalcohols 16 and 22 , respectively, were converted to methylene-bridged tetrahydro- ( 11 ) and hexahydro-3,1-benzoxazin-2-ones 12, 17, 23 and 3,1-benzoxazin-2-thiones 13, 14, 18, 24 . The exo-exo 3 and endo-endo 4 aminoalcohols were cyclized by means of ethyl arylimidates to tricyclic dihydro-1,3-oxazines 7a-d, 8a-d . The structures were confirmed by ir, 1H and 13C nmr spectroscopy. 相似文献
2.
For 12-- locked retinal analogues, thermal equilibria are established between 11-, 13--1c and 13--2c and between 9-, 11-, 13--1d and 9-, 13--2d; a photoisomerization occurs to transform 2c to --2a and 2d to 9--2b 相似文献
3.
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
4.
13C chemical shifts of nine N-substituted 2-amino-4H-3,1-benzoxazin-4-ones, the isomeric 3-substituted 2,4-(1H,3H)quinazolinediones, and the parent compounds of the two series are reported. Support is provided for the endocyclic position of the C=N bond in the former series of compounds. 相似文献
5.
trans- -Isopropenyl-4-methylene-spiro[2.x]alkanes ( and ) react at 0°C with CSI to give as major products the trans bicyclic cycloazanondienones (-) and as the minor products bicyclodihydro-azepinones ( and ), and the respective cis isomer of bicyclic cycloazanondienones ( and ). 相似文献
6.
J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of and [2+2]cycloadducts of benzyne to , - and , -1,5-cyclooctadiene, - and -cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described. 相似文献
7.
EI mass spectra of -η4,η4-[3,6-bis(methylene)-1,4-cyclohexadiene]-bis=(tricarbonyliron) complexes , are reported. The fragmentation pathway is rationalized by assuming a rearrangement of the -bis(tricarbonyliron) complexes into the -isomers under electron impact. 相似文献
8.
The 1H NMR parameters of methyl 3-substituted cis-4-halotetrahydro-2-oxo-3-furancarboxylates are reported, with assignments of the ring protons based on solvent-induced changes in the vicinal trans coupling constants, 3J(H-4, H-5). Preferred conformations, ce with a pseudo-equatorial halogen for the cis isomers and ta with a pseudo-axial halogen for the trans isomers, have been suggested on comparison of the magnitudes of J(trans) and J(gem) in both series. The 3J(13CH3, H-4) values measured for methyl cis-4-bromotetrahydro-3-methyl-3-furancarboxylate, methyl trans-4-bromotetrahydro-3-methyl-3-furancarboxylate and trans-3,4-dibromodihydro-3-methyl-2(3H)-furanone have confirmed the stereochemical assignments. 相似文献
9.
Hydroxylamine reacts with 1-alkyl-1,2-dihydro-3,1-benzothiazine-4thiones ( 1 ), giving 1-alky1-3-hydroxy-2,3-dihydro-1H-quinazoline-4-thiones ( 2 ). The same reagent, in neutral medium, converts 1-aryl-1,2-dihydro-3,1-benzothiazine-4-thiones ( 3 ) into 1-aryl-4-hydroxyimino-1,4-dihydro-2H-3,1-benzothiazines ( 4 ). In acidic medium, the same starting materials lead to 1-aryl-3-hydroxy-2-3-dihydro-1H-quinazoline-4-thiones ( 5 ). genrally with some quantity of the isomer 4 . Thiones 2 and 5 , as well as oximes 4 , heated at 200°, decomopose, yielding, in varying proportions, 1H-quinazoline-4-thiones ( 6 or 7 ), 1H-quinazoline-4-ones ( 9 ) and 2,3-dihydro-1H-quinazoline-4-thiones ( 11 ). Reacting with methyliodide, 1H-quinazoline-4-thiones ( 7 ) give 4-methylthioquinazolin-1-ium iodidies ( 12 ) which can be hydrolysed into 1H-quinazolin-4-ones ( 9 ). The latter are also obtained by reacting benzonitrile N-oxide with the corresponding thiones. 1-Aryl-1 H-quinazoline-4-thiones ( 7 ) react readily with nitrogen nucleophiles XNH2 to give 1-aryl-4-imino-1,4-dihydro-quinazolines diversely substituted on the imino group. While thiones 7 are S- methylated by methyl iodide, the corresponding 1-aryl-1H-quinazolin-4-ones (9), with the same reagent, ungergo a N-methylation, yielding 1-aryl-3-methyl-4-oxo-3,4-dihydroquinazolin-l-ium iodides ( 18 ). Structure have been confirmed by uv, ir and nmr spectra. 相似文献
10.
The racemic cis- and trans-5-butyltetrahydro-4-methylfuran-2-ones ( = whisky lactones) and their higher homologues tetrahydro-4-methyl-5-pentylfuran-2-ones ( = cognac lactones) have been prepared in 2–3 steps from 2-(trimethylsiloxy)furan. Regioselective alkylation of the latter afforded the 5-butyl- and 5-pentylfuran-2(5H)-ones which served as precursors for the stereocontrolled construction of either diastereoisomer of the beverage lactones. The structure and tautomerization of the diazomethane adducts of these 5-alkylfuran-2(5H)-ones are also described. 相似文献
11.
Youichiro Naito Yoshihisa Inoue Taizo Ono Yoshio Arakawa Chikara Fukaya Kazumasa Yokoyama Yoshiro Kobayashi Kouichi Yamanouchi 《Journal of fluorine chemistry》1984,26(4):485-497
Electrochemical fluorination of N-methyldecahydroquinoline afforded mainly a mixture of and N-(F-methyl)-F-decahydroquinoline, their rearranged isomers and F-propyl-F-cyclohexane arising from the cleavage at carbon-nitrogen bonds, in a ratio of approximately 2:4:6:3. N-Methyldecahydroisoquinoline was also fluorinated electrochemically to give a mixture of and N-(F-methyl)-F-decahydroisoquinoline, their rearranged isomers and 1-(F-ethyl)-2-(F-methyl)-F-cyclohexane in a ratio of approximately 4:4:6:1. No correlation was found between the and ratio of starting materials and that of the corresponding perfluorinated amines. Fluorination of N-methyl-1,2,3,4-tetrahydroquinoline gave much lower yields. 相似文献
12.
A stereoselectivity in an intramolecular cycloaddition of the olefinic -quinodimethanes 13 and 23 generated from the thermolysis of optically active 4β-[2-(4-methoxybenzocyclobutenyl)ethyl] -5α-methoxymethyl-3-phenyl-thio-methylenefuran-2-ones 12 and 22, respectively, is studied and a stereoselective synthesis of (+)--4,5-( 4-methoxybenzo) -1β,7aβ-(2α-methoxymethyl-5-oxofuro)hydrindane 1 is also described. 相似文献
13.
Oxidation of the complexes -[M(CNR)2(dppe)2] (A) (M = Mo or W; R = Me, But or CH3C6H4-; dppe = Ph2PCH2CH2PPh2) with diiodine or silver (I) salts gives the paramagnetic cations -[M(CNR)2(dppe)2]+, (M = Mo, R = CH3C6H4-; M = W, R = But) and -[M(CNR)2(dppe)2]2+ (M = Mo, R = Me or CH3C6H4-; M = W, R = Me or But). Mixtures of products are generally produced when dichlorine or dibromine are the oxidising agents, however pure salts, the seven-coordinate complex cations [MX(CNC6H4CH3-)2(dppe)2]+ (B, X = Cl or Br) have been isolated. A simple molecular orbital scheme is proposed for complexes (A) and used to discuss their electronic spectra and their oxidation. 相似文献
14.
The enamino-thione, 1c, reacts with acrylonitrile and 2-chloroacrylonitrile at room temperature to give 3,4-dihydro-4-(1-pyrrolidinyl)-2-thiopyrans, 4 and 5, respectively. The reaction between 1-aryl-3-(1-pyrrolidinyl) (piperidino)-apropene-1-thiones, 1a-c (1d-f), and dimethyl acetylenedicarboxylate gives 4-(1-pyrrolidiny)(piperidino)-4-thiopyrans, 6a-c (6d-f). Compounds 1a-c (1d-f) and ethyl propiolate produce 2-(1-pyrrolidinyl) (piperidino)-2-thiopyrans, 8a-c (8d-f), and a new type of rearrangement is observed. The 2-thiopyran, 9, is formed from 1b and ethyl 3-propiolate, which elucidates the mechanism. 1H and 13C NMR data of 6 and 7 are discussed. 相似文献
15.
Summary Acid-catalyzed reaction of 2-arylidenecyclohexanones1 with N-substituted dithiocarbamic acids2 gave open-chain addition products3 and4. Dehydration of3 and4 afforded only one of the three possible isomeric N-substituted 4H-3,1-benzothiazine-2(1H)-thiones5 and6.
Synthese von partiell gesättigten N-substituierten 4H-3,1-Benzothiazin-2-(1H)-thionen
Zusammenfassung Die säurekatalysierte Reaktion von 2-Arylidencyclohexanonen1 mit N-substituierten Dithiocarbaminsäure2 ergab die offenkettigen Additionsprodukte3 und4. Die Dehydratation von3 und4 führte ausschließlich zu einem der drei möglichen N-substituierten 4H-3,1-Benzothiazin-2(1H)-thion-Isomeren5 und6.相似文献
16.
Shigeyuki Mayama Toshikazu Tani Tamio Ueno Kazumasa Hirabayashi Tadakazu Nakashima Hiroshi Fukami Yukio Mizuno Hiroshi Irie 《Tetrahedron letters》1981,22(22):2103-2106
The major phytoalexin from oat leaves has been identified as 2-[2-(4-hydroxyphenyDethenyl] -6-hydroxy-4H-3,1-benzoxazin-4-one (). 相似文献
17.
Max Herberhold Cornelius G. Kreiter Gűnter O. Wiedersatz 《Journal of organometallic chemistry》1976,120(1):103-130
The temperature-dependent 1H NMR spectra of acetylacetonatebis(ethylene)-rhodium, (acac)Rh(C2H4)2 (I), of some related complexes containing methoxy-substituted ethylenes have been measured in toluene-d8 solution. Both monosubstituted [(acac)Rh(C2H4)(olefin), olefin = tetramethoxyethylene (II), - and -dimethoxyethylene (III and IV)] and disubstituted [(acac)Rh(olefin)2, olefin = - and -dimethoxyethylene (V and VI), methyl vinyl ether (VII)] derivatives of I have been investigated with respect to hindered intramolecular movements of the ligands. The barriers of olefin rotation increase with an increasing number of methoxy substituents. When the olefin rotation is frozen out; the methoxy substituents of the olefins tend to be turned away from the acetylacetonate ligand unless steric interaction occurs between the two π-coordinated olefins. A hindered movement of the acetylacetonate ligand has been observed in II and V. For this movement which is independent of the olefin rotation, a degenerate rearrangement is proposed of the tetragonal-planar complexes via a tetrahedral transition state. 相似文献
18.
The reaction of both - and -2-amino-1-(1-phenylvinyl)- cyclopentanols with aldehydes affords -2-alkyl--3a-aryl-4-oxo-octahydro indoles stereoselectively. 相似文献
19.
- and -2-Methylamino and 2-benzylamino-3-hydroxymethylbicyclo [2.2.1]heptanes and the corresponding bicycio [2.2.1] heptenes ( -, -) were synthesized from β-amino acid esters containing the norbornane or norbornene skeleton (-). The aminoalcohols were converted to 5,8- methano -3,1-benzoxazines by reaction with formaldehyde. As established by 1H and 13C NMR spectroscopy, the predominant conformation is () for the , and () for the derivatives. 相似文献
20.
Géza Stájer LászlÓ Mód Angela E. Szabó Ferenc Folöp Gábor Bernáth Pál Sohár 《Tetrahedron》1984,40(12):2385-2393
The -- amino acid with norbornene skeleton was converted into 2-aryvl---1,3-oxazin-4-ones -. These compounds, similarly to the isomers - studied by us earlier, undergo retrodiene decomposition under mild conditions to give 2-aryl-6-l,3-oxazin-6-ones (-) in 50-60% yield. The ratio of the decomposition rate constants of the tricyclic and -1,3-oxazin-4-ones, measured in toluene solution, is about 2. 相似文献