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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 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
4.
o-Lithomethylphenyl isocyanide is reacted at ?78° with isocyanates and isothiocyanates to produce o-isocyanophenyl-acetamides and -acetothioamides . Isocyanides and are cyclized to indole-3-carboxamides and -3-thiocarboxamides via lithiathion, respectively. Isocyanides are also cyclized by Cu2O catalyst to produce 4,5-dihydro-1,3-benzodiazepin-4-ones with . 相似文献
5.
is silylated, enolised with KH and converted by the addition of acid to a mixture of epimeric aldehydes and . Subsequent acetylation, oxydation and deacetylation of affords 6-Epi-gibberellin-A3 (). 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.
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
8.
Gunda I. Georg 《Tetrahedron letters》1984,25(35):3779-3782
Addition of dianions of 3-hydroxybutyrates to benzylideneaniline results in direct formation of -3-(l-hydroxyethyl)-1,4-diphenyl-2-azetidinone with 95% diastereoselectivity. Inversion of the configuration at Cα, gives the desired -2-azetidinone in high yield. 相似文献
9.
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
10.
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
11.
-Dihydrobenzofuro[2,3-c]quinolone () and -dihydrobenzofuro-[3,2-c]quinolone () undergo photorearrangement, characteristic to the benzodihydrofuran system, leading to 3--hydroxyphenylquinolone (). A plausible mechanism involving a cyclopropyl dienone () was discussed. 相似文献
12.
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
13.
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
14.
For the first time a perfluoroalkanesulfonylallene, the 1-phenyl-3-(trifluoromethanesulfonyl)-propadiene () was synthesized. is reacts already at room temperature with cyclopentadiene to form the adduct . 相似文献
15.
N,N-Dimethylformamide () and N,N-dimethylpivalamide () react with carbonyl chloride isocyanate () in the presence of antimony pentachloride to afford the amino substituted 1-oxa-3-azabutatrienium hexachloroantimonates ,. An X-ray diffraction analysis of confirms the proposed structure. The heterocumulenes , react with aldehydes, ketones and tertiary carboxamides to give the amino substituted 2-azaallenium salts - in high yields. 相似文献
16.
At 60° the title compound isomerises quantitatively to aromatic products and . A kinetic study reveals the influence of solvent polarity and of acid on the rate and direction of this reaction. 相似文献
17.
Vincadifformine (), eburcine () and 3-epieburcine () in racemic forms have been synthesized from 1,2-dehydroaspidospermidine () by introduction of methoxycarbonyl group to C(3)-position of aspidosperma skeleton. 相似文献
18.
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
19.
Treatment of , , and with methyllithium affords , ; , ; and respectively in serviceable yields carbenoid cyclization. 相似文献
20.
PMR analysis assigns twist and chair predominant conformations to the Rp and Sp diastereomers, respectively ( and ), of thymidine 3′,5′-cyclic N,N-dimethylphosphoramidate, . The twist conformer population of is about 64 (acetone) to 75% (toluene). 相似文献