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Molecular model enantiomer

Make a molecular model of one of the enantiomers of 3 buten 2 ol and the 2 butanol formed from it... [Pg.289]

If they are stereoisomers are they enantiomers or diastereomers" (Molecular models may prove useful in this problem )... [Pg.319]

Excluding enantiomers there are three isomeric cyclopropanedicarboxyhc acids Two of them A and B are constitutional isomers of each other and each forms a cyclic anhydnde on being heated The third diacid C does not form a cyclic anhydride C is a constitutional isomer of A and a stereoisomer of B Identify A B and C Construct molecular models of the cyclic anhy dndes formed on heating A and B Why doesn t C form a cyclic anhydride" ... [Pg.883]

The property of chirality is determined by overall molecular topology, and there are many molecules that are chiral even though they do not possess an asymmetrically substituted atom. The examples in Scheme 2.2 include allenes (entries 1 and 2) and spiranes (entries 7 and 8). Entries 3 and 4 are examples of separable chiral atropisomers in which the barrier to rotation results from steric restriction of rotation of the bond between the aiyl rings. The chirality of -cyclooctene and Z, -cyclooctadiene is also dependent on restricted rotation. Manipulation of a molecular model will illustrate that each of these molecules can be converted into its enantiomer by a rotational process by which the ring is turned inside-out. ... [Pg.82]

The three water ligands located at meridional positions of the J ,J -DBFOX/Ph aqua complexes may be replaced by another molecule of DBFOX/Ph ligand if steric hindrance is negligible. Based on molecular model inspection, the hetero-chiral enantiomer S,S-DBFOX/Ph looks like a candidate to replace the water ligands to form the heterochiral meso-2 l complex J ,J -DBFOX/Ph-S,S-DBFOX/... [Pg.260]

Figure 1.3 Molecular models showing the two enantiomers resulting from the loss of mirror plane symmet7 on adsorption with the molecular plane parallel to the substrate. The separation of enantiomers observed by STM is identified by the relative displacement of adjacent monomers within the double chain. (Reprinted with permission from Ref. [6]. Copyright 2001, American Physical Society.)... Figure 1.3 Molecular models showing the two enantiomers resulting from the loss of mirror plane symmet7 on adsorption with the molecular plane parallel to the substrate. The separation of enantiomers observed by STM is identified by the relative displacement of adjacent monomers within the double chain. (Reprinted with permission from Ref. [6]. Copyright 2001, American Physical Society.)...
Figure 1.6 The left-hand panel shows a molecular model of the glycinate/Cu l 1 0 structure with both enantiomers present in the heterochiral (3 x 2) unit cell, superimposed on an STM image of this surface. (Adapted with permission from Ref. [12]. Copyright 2002,... Figure 1.6 The left-hand panel shows a molecular model of the glycinate/Cu l 1 0 structure with both enantiomers present in the heterochiral (3 x 2) unit cell, superimposed on an STM image of this surface. (Adapted with permission from Ref. [12]. Copyright 2002,...
The high levels of enantioselectivity obtained in the asymmetric catalytic carbomagnesa-tion reactions (Tables 6.1 and 6.2) imply an organized (ebthi)Zr—alkene complex interaction with the heterocyclic alkene substrates. When chiral unsaturated pyrans or furans are employed, the resident center of asymmetry may induce differential rates of reaction, such that after -50 % conversion one enantiomer of the chiral alkene can be recovered in high enantiomeric purity. As an example, molecular models indicate that with a 2-substituted pyran, as shown in Fig. 6.2, the mode of addition labeled as I should be significantly favored over II or III, where unfavorable steric interactions between the (ebthi)Zr complex and the olefmic substrate would lead to significant catalyst—substrate complex destabilization. [Pg.188]

Molecular modeling calculations give important insight into the origin of such a large enantioselectivity. Unlike the rigid /3-CD, the hnear maltoheptaose allows each enantiomer of phenylalanine to find the most favorable conformation. The phenyl group of L-phenylalanine is oriented towards the C6 center of the hosts, while that of D-phenylalanine is oriented towards the C2 and C3 centers of the hosts. [Pg.224]

To explain the observed optical induction, a substrate was incorporated into the molecular model of the protein. A substrate such as a-ketoglutarate could be included in the protein model with a geometry that allowed stereoselective protonation of the quinoid intermediate by solvent, consistent with the enantiomeric excess (ee) of the 1-stereoisomer product. Moreover, the geometry consistent with production of the d-enantiomer appeared too sterically crowded for most substrates. However, pyruvic acid, which was the only substrate to favor the d-enantiomer product, was small enough to adopt the alternative geometry and also had the potential to interact with an arginine group. [Pg.11]

Each isomer is the mirror image of the other and they are known as optical isomers or enantiomers. But all molecules have mirror images, yet they do not all exhibit optical isomerism. What makes lactic acid different is that its two isomers are non-superimposable. You should make molecular models of these optical isomers to convince yourself that one isomer cannot be superimposed on the other. [Pg.54]

Given atomic coordinates for a particular conformation of a molecule and some property value assigned to each atom, one can easily calculate a chirality function that distinguishes enantiomers, is zero for an achiral molecule, and is a continuous function of the coordinates and properties. This is useful as a quantitative measure of chirality for molecular modeling and structure-activity relations. [Pg.427]

CL Copper, JB Davis, RO Cole, MJ Sepaniak. Separations of derivatized amino acid enantiomers by cyclodextrin-modified capillary electrophoresis Mechanistic and molecular modeling studies. Electrophoresis 15 785-792,... [Pg.113]

Using the crystal structures of two related RED enzymes of lignan biosynthesis, a provisional molecular model has been produced for the M. sativa IFR. A smaller binding pocket in the protein, in comparison to the other enzymes, is suggested to account for the specific enantiomer binding and processing of IFR. [Pg.176]

Identify the relationship in each of the following pairs. Do the drawings represent constitutional isomers or stereoisomers, or are they just different ways of drawing the same compound If they are stereoisomers, are they enantiomers or diastereomers (Molecular models may prove useful in this problem.)... [Pg.326]

A cyclic compound that has two differently substituted asymmetric carbons will have 22 = 4 optical isomers. These will consist of pairs of cis and trans enantiomers. When the asymmetric centers have identical substituents, the cis isomer will have an internal reflection plane and is called a meso form. The meso forms of ds-l,2-dicarboxycyclopropane are shown in panels (b) and (d) of Figure 1.16 in a line angle drawing and as a molecular model. [Pg.56]


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See also in sourсe #XX -- [ Pg.5 ]




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Molecular enantiomers

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