Chiral molecules drawing

Let s return to bromochlorofluoromethane as a simple example of a chiral molecule. The two enantiomers of BrCIFCH are shown as ball-and-stick models, as wedge-and-dash drawings, and as Fischer projections in Figure 7.6. Fischer projections are always generated the same way the molecule is oriented so that the vertical bonds at the chirality center are directed away from you and the horizontal bonds point toward you. A projection of the bonds onto the page is a cross. The chirality center lies at the center of the cross but is not explicitly shown. 

Drawing the Three-Dimensional Structure of a Chiral Molecule... 

A Draw chiral molecules that meet the following descriptions ... 

Draw the nine chiral molecules that have the formula CgH Br. 

Drawing a chiral molecule (enantiomer) On a plane paper, chiral molecules can be drawn using wedge bonds. There are also a few other methods that use horizontal bonds representing bonds pointing out of the paper and vertical bonds pointing into the paper. Some examples are given below. 

Following the Cahn-Ingold-Prelog system, it is now possible to draw the structures of (i )- and (5)-enantiomers of various chiral molecules, for example 2,3-dihydroxypropanoic acid, where the priorities are 1 = OH, 2 = COOH, 3 = CH2OH and 4 = H. 

I would like to draw attention here to some work on chiral molecules, which allows very fundamental tests of symmetries in physics and chemistry. The experiment outlined in Scheme 2 [4] allows us to generate, by laser control, states of well-defined parity in molecules, which are ordinarily left handed (L) or right handed (R) chiral in their ground states. By watching the time evolution of parity, one can test for parity violation and I have discussed in detail [4-6] how parity violating potentials AEpv might be measured, even if as... 

These drawings are clear but can be cumbersome, particularly for more complex molecules, and we shortly shall describe other means of representing the configurations of chiral molecules. 

Fischer projection (Section 7.8) A two-dimensional drawing of a chiral molecule in which the chirality center is represented as a cross with the atom at its coiter. Although the four bonds to the chirality center are shown in the plane of the page, the horizontal bonds project above the plane of the page and the vertical bonds project behind the page. 

This may not be obvious in the normal drawing (which has a centre of symmetry), but rotation around the central C-C bond clearly shows the plane of symmetry. Neither plane nor centre of symmetry may be present in a chiral molecule, but a C2 axis is allowed (Chapter 16). 

Draw chiral molecules that meet the following descriptions (a) A chloroalkane, CgHnCl (b) An alcohol, C Hi40... 

When learning to visualize chiral molecules, it s best to begin by buildii molecular models. As more experience is gained, it becomes easier to draw pictures and work with mental images. To do this successfully, though, a standard method of representation is needed for depicting the three-... 

Eight alcohols have the formula C5H12O. Draw them. Which are chiral Draw the nine chiral molecules tliat have the formula CgHiaBr. 

Dispariure, CisHasO, is a sex attractant released by the female gypsy moth, Lyman-tria dispar. The H NMR spectrum of dispariure shows a large absorption in the alkane region, 1-2 6, and a triplet at 2.8 fi. Treatment of dispariure, first with aqueous acid and then with KMn04, yields two carboxylic acids identified as undecanoic acid and 6-methylheptanoic acid. (KMn04 cleaves 1,2-diols to yield carboxylic acids.) Neglecting stereochemistry, propose a structure for dispariure. The actual compound is a chiral molecule with 7R.8S stereochemistry. Draw dispariure, showing the correct stereochemistry. 

Q1. Give stereochemical diagrams for (i) m-cydobutane-l,2-dicarboxylie acid (56) (ii) //fm.y-cydobutane-l,2-dicarboxyiic acid (57) (iii) m-eydobutane-l, 3-dicarboxylic acid (58) (iv) ircms-cydobutane-l,3-dicarboxy ic acid (59). Only one of the above compounds is chiral. Give the RfS configuration of the stereoisomer that you draw for the only chiral molecule in (i)-(iv). 

If a carbon atom (or other type of atom) has four different substituents, that carbon atom forms a chiral center (also known as a stereocenter). Chiral molecules often have one or more stereocenters. When drawing molecules, stereocenters arc usually indicated with an asterisk near the carbon. 

Isopropanol is prepared by reacting propylene (CH3CHCH2) with sulfuric acid, followed by treatment with water, (a) Show the sequence of steps leading to the product. What is the role of sulfuric acid (b) Draw the structure of an alcohol that is an isomer of isopropanol, (c) Is isopropanol a chiral molecule (d) What property of isopropanol makes it useful as a rubbing alcohol ... 

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