DEFINICION DE ESTEREOQUIMICA PDF

La química en tres dimensiones se conoce como estereoquímica. En la tabla se resumen algunas definiciones básicas relacionadas con la estructura. Definición El ibuprofeno es un antiinflamatorio no esteroideo (AINE), Estereoquímica El ibuprofeno se produce industrialmente en forma de. grupos funcionales organicos estereoquimica practicas de laboratorio de la práctica deberemos conocer bien la definición de sublimación y el concepto de.

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In the symmetrical boat conformation of cyclohexane, eclipsing of bonds results in torsional strain. Comments The driving force in all pericyclic rearrangement including the Claisen rearrangement results from a contest between the ring strain in the transition state that should lower and the tendency to form the carbonyl double bond that should increase.

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Carruthers in ‘Some modern methods of organic synthesis’, and we have proposed didactical and mechanistic views for them. The methyl group is axial defimicion one conformation, and equatorial in the other. Nomenclature of Alkyl Groups Caption: All the carbon-carbon bonds are eclipsed, generating torsional strain that contributes to the total ring strain.

This puckered conformation reduces the eclipsing of adjacent CH2 groups. Interconversion between chair conformations require that cyclohexane go through its higher energy conformations.

Esta interferencia es llamada interacciones 1,3-diaxial. The reaction takes place in a suprafacial manner with respect to the allylic part [11]. There is a correlation between chiral centers at C-2 and C-3 in compounds 2 and 4 Fig.

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Conformational Analysis of Butane Caption: Theoretical mechanistic approach to diasteroselective synthesis of cis-1,2-dialkenylcyclopropanols and subsequent oxy-Cope rearrangement by Jin Kun Cha et al, Rev. Groups like tert-butyl are so bulky that it will force the chair conformation where it is in the equatorial position, regardless of other groups present. Alkyl substituents on cyclohexane rings will tend to be equatorial to avoid 1,3-diaxial interactions.

Torsional energy of butane.

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Chair Conformations of trans-1,3-Dimethylcyclohexane Caption: Chair Conformation of Cyclohexane Caption: Conformations of Ethane Caption: Some groups are so bulky that they are extremely hindered in axial positions. The angle compression of cyclopropane is Torsional strain in cyclopropane. Esterroquimica Conformations of cis-1,3-Dimethylcyclohexane Caption: In this case both chairs have the same energy, and they are present in equal amounts.

The chair conformation is most stable, followed by the twist boat. The aim of this series of studies is to help students to have a graphical view of organic synthesis reactions of diverse nature. Any of the configurations at the chiral carbon formed C-3 in 2 or 4 can be obtained if a change in the stereochemistry of double bond of the allylic portion is done.

Cyclohexane can adopt four non-planar conformations: Comparison of the boiling points of the unbranched alkanes blue with those of some branched alkanes red. To convert between these two conformations, the molecule must pass through the unstable half-chair estereoquiimica. Since the methyl group occupies more space than a hydrogen, the torsional strain will be 0.

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Estructura y Estereoquímica de Alcanos

We elaborated too, the mechanisms for the conversion of allylic ester into the E-ketene acetal or the Z-ketene acetal and subsequent acid formation including the example of the E-crotyl propanoate and the Z-crotyl propanoate. Hemos propuesto mecanismos para este hecho. Chair-chair interconversion of methylcyclohexane.

The melting point curve for n-alkanes with even numbers of carbon atoms is slightly higher than that for alkanes with odd numbers of carbons. We proposed mechanisms for this feature. The staggered dw are lower in energy than the eclipsed conformation because the staggering allows the electron clouds of the C-H bonds to be as far apart as possible.

La eclipsada es 3. Los botones se encuentran debajo. There are two possible geometric isomers for decalin: The molecular formula of alkanes is CnH2n, two hydrogen less than an open chain esetreoquimica. The C-C bond distance is 1.