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1.
Pyrolysis of homoadamant-3-ene (), generated from 1-adamantylcarbene (), leads to the same three olefins (, , and ) that are produced from pyrolysis of 3-homoadamantyl acetate (). 相似文献
2.
A. Zanarotti 《Tetrahedron letters》1982,23(38):3963-3964
Vinyl quinone methide () reacts with polyphenols to give cinnamylphenols () and neo-flavanoids (). Oxidation of cinnamylphenol (b) leads to malvidin () via the isolated intermediate flav-3-en-3o1 (b). 相似文献
3.
The E- and Z-γ-methoxy-allylboronates and add cleanly to aldehydes to give diastereoselectively the adducts and . 相似文献
4.
The total synthesis of a 3-thia- and a 3-aza-1-dethiacepham ( and ) are described. Neither compound possessed antibacterial activity . . An unsaturated analog, a 3-aza-1-dethiaceph-1-em exhibited weak antibacterial activity. 相似文献
5.
The action of either cyanate or acetate ions on -3-mesyloxyflavanones led to the formation of flavones and aurones while the reaction with the respective S-nucleophiles (thiocyanate and thioacetate ions) resulted in -and -3-thiocyanato- and 3-acetylthioflavanones ( and ). The participation of the concurrent nucleophilic substitution, β-elimination and elimination with ring-contraction is dependent on the “hard-soft” character of the nucleophile and the increase of the “soft” character favours the displacement. 相似文献
6.
During the hydrogenation of the Δ3(3a)-4-hydrindenones or on Pd or Ni, we observe a shift of the double bond to Δ3a(7a)-4-hydrindenones and . The absolute configuration established for ketones and shows that the reaction is a suprafacial process. By deuteriation experiments, we observe that the reaction is irreversible and occurs with a molecular hydrogen exchange. 相似文献
7.
Aziridines react with trifluoromethyl hypofluorite at ? 40°C to produce mixtures of 1-(aziridine)carbonyl fluoride and 1-fluoroaziridine , the proportions of which depend on steric effects. Several compounds react with starting materials to give 1, 1′-(carbonyl)bisaziridines . Most compounds and all compounds are isolated. Chemical properties and ir and nmr data of , , are described; the formation of an isocyanate and a substituted urea from a compound is observed. A mechanism for this reaction is suggested. 相似文献
8.
Yoshimitsu Nagao Kaoru Seno Kohji Kawabata Tadayo Miyasaka Sachiko Takao Eiichi Fujita 《Tetrahedron letters》1980,21(9):841-844
3-Acylthiazolidine-2-thiones () were easily prepared and they were treated with several amines in dichloromethane to give amides in very high yields within a short time. Aminoalcohols and aminophenols were selectively converted into acylaminoalcohols and acylaminophenols, respectively, by this reaction. One can monitor the reaction by disappearance of the yellow color of the starting material . Some amide alkaloids (–) have effectively been synthesized. 相似文献
9.
Giovanni Fronza Claudio Fuganti Piero Grasselli Giuseppe Pedrocchi-Fantoni 《Tetrahedron letters》1981,22(50):5073-5076
The synthesis of the N-benzoyl derivatives of - (10),- (13) and - (-vancosamine) (12) 2,3,6-trideoxy-3--methyl-3-aminohexose from the (2,3) diol (1) prepared in fermenting bakers' yeast from α-methylcinnamaldehyde and acetaldehyde is reported 相似文献
10.
3-Methylisoxazolo[4,5-c]pyridine on reduction with BH3:THF gave, via the isolable complex , the tetrahydroisoxazolopyridine . The presence of two chlorine atoms at the 4 and 6 positions directed borane attact to the isoxazole ring, yielding the aminoethylpyridine . Both types of reduction were obtained with 6-chloroisoxazolo[4,5-c]pyridine . 相似文献
11.
Reaction of azetidinone phosphoranes with aldehyde gave the olefins , which were converted into carbapenem esters 6 in 4 steps. Hydrogenation of gave the title compounds. 相似文献
12.
Alcohols and , prepared from , underwent completely stereospecific etherification to give 1-oxacephams and , which were converted into the 1-oxacephem nucleus via and . Functionalization at C-3′ in and was unsuccessful. 相似文献
13.
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
14.
Wojciech Dmowski 《Journal of fluorine chemistry》1982,20(5):589-598
Acidic hydrolysis of 1-(o-methoxyphenyl)pentafluoropropene gave o-hydroxy-2,3,3,3-tetrafluoropropiophenone and o-methoxy-2,3,3,3-tetrafluoropropiophenone . Compound when treated with aqueous potassium hydroxide or methanolic sodium methoxide gave 3-fluoro-4-hydroxycoumarin . Structure of has been established by spectral means and some chemical reactions. The cyclisation mechanism of is discussed. 相似文献
15.
Masako Nakagawa Takako Maruyama Kazuyuki Hirakoso Tohru Hino 《Tetrahedron letters》1980,21(50):4839-4842
Oxytryptamine was converted to kynurenamine , benzo-oxazinone , and 3-hydroxy derivative b in NaOH-MeOH in the presence of oxygen, whereas undergoes N,N′-transacylation to give the isomeric product in argon atmosphere. 相似文献
16.
Simon J. Edge W.David Ollis Julia Stephanidou Stephanatou J.Eraser Stoddart David J. Williams Kwamena A. Woode 《Tetrahedron letters》1981,22(23):2229-2232
The tri-3-methyltrianthranilide derivatives ()–() have been synthesised. Dynamic 1H n.m.r. spectroscopy indicates that the ,′,″-trimethyl derivative () exists in solution as slowly ring inverting ( ? *) enantiomeric helical conformations. X-Ray crystallography shows that the ,′-dimethyl-″-benzyl derivative () undergoes spontaneous resolution when it crystallises as a 1:1 adduct from toluene. The host molecules adopt a helical conformation (Figure 1) within a lattice structure that contains chiral channels (Figure 2) occupied by guest solvent molecules. 相似文献
17.
2β-Fluoro-1α-hydroxyvitamin D3() was prepared from 1,2α-epoxy-cholest-5-en-3β-yl tetrahydropyranyl ether( via 2β-fluorocholest-5-ene-1α, 3β-diol(). 相似文献
18.
An azaanalog of adamantene, 2-azaadamant-1-ene () and 4-azaprotoadamant-3-ene () were generated in the nonstatistical ratio via photolysis of 3-azidonoradamantane (). The highly strained and could not be isolable but were trapped by MeOH. Acidolysis of was also reported, and discussed in comparison with the photolysis. 相似文献
19.
Josefina Garcia Robert Greenhouse Joseph M Muchowski Jose Antonio Ruiz 《Tetrahedron letters》1985,26(15):1827-1830
2-Alkyl-3-cyanoindoles are obtained when 1-alkylmethyl-2-chloro-(or 2-phenylsulfonyl)-3-phenylsulfonylindoles are reacted with excess azide ion (90°/DMF). The reaction is considered to occur by a fragmentation recombination process in which the Schiff's base is of central importance. This proposal is supported by the formation of 2-substituted indole-3-carboxylates from aldehydes and the α-phenylsulfonyl--aminophenylacetic acid ester derivative . 相似文献
20.
Stereospecific conversion of β-hydroxyallylglycine derivatives into (2, 3, 4) 1 and (2, 3, 4) 2 halo- or mercuri-lactonization has been described. 相似文献