ESTEREOQUIMICA DE ALCANOS Y CICLOALCANOS PDF
Download Wade03 estructura y estereoquimica de alcanos . leccin 5. alcanos y cicloalcanos – orgnica 2 leccin 5. Documents. estereoquímica introducción los isómeros estructurales se definen como isómeros, todos aquellos compuestos químicos que poseen igual fórmula global, . Estereoquímica es el término aplicado a los aspectos tridimensionales de la estructura CAPÍTULO TRES Conformaciones de alcanos y cicloalcanos.
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Estructura y Estereoquímica de Alcanos
Folding gives partial relief from the eclipsing of bonds, as shown in the Newman projection. Totally Eclipsed Conformation of Butane Caption: Angle strain in cyclopropane. Alcanos ramificados tienen p.
The following figure shows the severe steric interactions in a chair conformation with a t-butyl group axial. Their physical properties resemble xlcanos of alkanes.
Pure conformers cannot be isolated in most cases, because the molecules are constantly rotating through all the possible conformations. Three of these conformations are given specific names. May be cycloalkyl attachment to chain. Methane is perfectly tetrahedral, with the The different arrangement formed by estereoquikica about a single bond are called conformations, and a specific is called conformer.
Wade03 estructura y estereoquimica de alcanos – [PPT Powerpoint]
Longer chained alkanes have greater surface area and can have more surface contact and more induced dipoles than branched ee with smaller surface areas.
Chapter 3CyclohexaneCombustion data shows its unstrained. The eclipsed conformation is about 3.
Ambas conformaciones tienen un metil axial y otro ecuatorial. Newman Projections of Butane Caption: In the Newman projection it estereoquijica easier to see the steric interaction between the methyl substituent and the hydrogens and carbons of the ring. There is steric hindrance between these hydrogens so the molecule twists a little producing the twist boat conformation which is 1.
El Cis-1,3-dimetilciclohexano puede tener ambos grupos axiales o ecuatoriales. Listed in Table 3.
Since the methyl group occupies more space than a hydrogen, the torsional strain will be 0. Post on Apr views. Cyclohexane can adopt four non-planar conformations: Same Esstereoquimica Chains Caption: Torsional strain in cyclopropane.
Wade03 estructura y estereoquimica de alcanos
Conformations of Cyclopentane Caption: This puckered conformation reduces the eclipsing of adjacent CH2 groups. Often, the longest chain with the most substituents is not obvious. In the alcaanos molecule, the boat conformation is skewed to give the twist boat, a conformation with less eclipsing of bonds and less interference between the two flagpole hydrogens.
Substituents on a carbon chain are called alkyl groups. Neopentane, most highly branchedFive possible isomers of hexane,18 isomers of octane and 75 for decane!
Molecules constantly rotate through all the possible conformations. The methyl group is axial in one conformation, and equatorial in the other. Parentheses are used around the complex branch name. An equatorial methyl group will be anti to estereqouimica C3.
The axial bonds are directed vertically, parallel to the axis of the ring.
The bond angles are The unfavorable conformation has both methyl groups in axial positions, with a 1,3-diaxial interaction between them.