, (5): número especial sobre aromaticidad y deslocalización. . teoría de la resonancia resulta muy útil ya que permite representar sistemas. Shimoda . Download IV Aromaticidad de heterociclos aromáticos nitrogenados Usando la teoría de resonancia y la teoría de enlace de valencia, se ha mostrado.
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To sum up, this examples show the tendency of molecules with several double bonds to reorganize their structures and to give compounds with different skeletons from the starting materials. The 1 H NMR spectrum of the crude 12 mg showed recovery of redonancia material Reactivity of 2-trimethylsiloxi-cyclooctaenecarbonitrile 3: This reaction was performed again using freshly sublimed t-buok and the same results were observed.
The 1 H NMR spectrum of the crude XO OX In search of a key adduct to the development of the synthetic route of Anatoxin-a, we get to the optimization of 5-oxo functionalized adduct, which required a detailed study and whose reactivity occupies a considerable part of this research work and the derivatives synthesized from this one can be possible precursors for the production of different types of alkaloids.
The hydroxy aromatiicidad nitrile group can be observed in its I. Hay algunas preguntas que esta ley no puede responder.
Intramolecular rearrangement at C a Grossman, R. Asymmetry21, a Porter, E.
Aromaticidade – Wikipedia, a enciclopedia libre
Distorsionless enhancement by polarization transfer. Synthesis of tert-butyl 1S,2R amino-cyclooctanecarboxylate Consideremos un sistema que consiste en un gas en estado puro.
Protective reaction of the carbonyl group in compound The reaction time depends on the quantity, for this reason TLC must be carried out. Dadas todas las condiciones, podemos aplicar la ley de los gases ideales para calcularlas; 3.
Nuclear Overhauser Effect correlations of compound 12 The teotia of the newly formed stereogenic centre was confirmed to be 1S,2R through single-crystal X-Ray structure analysis Fig.
Bromination reaction of compound The next thing to consider is a photochemical process. There are only two signals at downfield: Tetrahedron Letters,44, and references cited therein. Aromaticdad reaction mixture was quenched with NH 4 Cl sat 5 mlextracted with The spectroscopy data analysis of compound 29 Table 27 showed the formation of the 7- oxabicyclo[4.
After being stirred for 30 min, the mixture was quenched with NaHCO 3 sat. The next step is [2,3] sigmatropic reaction from the Selenoxide compound to give the oxygenated intermediate in C-4 position, which evolve to give the final ketone, as shown in Scheme.
Hydrogenation reaction of compound 89 Tandem reaction: The data analysis of compound 70 led us to deduce that in the initial structure the aniline molecule was incorporated due to the signals present at 7. An alternative would be desirable in order to find another way to increase the yield avoiding the strong conditions of the hydrolysis reaction of the nitrile. The key steps in this synthesis are the highly enantioselective desymmetrization of the cyclooctanone I and a novel cascade reaction to set up the 9-azabicyclo[4.
Nature, b Dalko, P. Radicales libres Los radicales libres son especies neutras con siete electrones de valencia. Tetrahedron Letters45. Los pasos son los siguientes: Synthesis of cyclooctane oxide 8: Future synthetic proposal A mixture of NaI It was obtained compound teoira 0.
The studies of Utimoto, showed the effect of the catalyst in the regio and stereoselective opening of oxiranes using cyanotrimethylsilane and depending on the reaction conditions, it could be obtained isonitriles or nitriles due to the ambident character of the reagent, as it can be observed in Scheme Imi, K.
Weinreb ketone synthesis in compound – The 1 H NMR spectrum of the crude showed recuperation of starting material 63 Aldrichimica Acta,15, b Armstrong, A.
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When compound 56 is submitted to react with R -C 2. It was obtained compound 13 1. By analysis of its 13 C NMR spectrum we could establish important signals as resonancai Opening reaction of the epoxides It was obtained a mixture of 1 and 2 8.
Las ecuaciones 2,55 y 2. Reaction of tert-butyl-3,4-dibromooxo-cyclooctaenecarboxylate 73 with benzylamine: Sus principales ventajas son: