Chair conformational structures, drawing

Problem 9.16 (a) Draw the possible chair conformational structures for the following pairs of dimethylcy-dohexanes (i) cis- and trans-1,2-, (ii) cis- and frans-1,3- (iii) cis- and trans-lA-. (b) Compare the stabilities of he more stable conformers for each pair of geometric isomers, (c) Determine which of the isomers of limethylcyclohexane are chiral. <... 

Problem 9.14 (a) Draw the possible chair conformational structures for the following pairs of dimethylcyclohex-... 

A set of guidelines will help you draw chair conformational structures that are clear and that have unambiguous axial and equatorial bonds. 

Notice in Fig. 4.18a that sets of parallel lines define opposite sides of the chair. Notice, too, that equatorial bonds are parallel to ring bonds that are one bond away from them in either direction. When you draw chair conformational structures, try to make the corresponding... 

Now, try to draw some chair conformational structures for yourself that include the axial and equatorial bonds. Then, compare your drawings with those here and with actual models. You will see that with a little practice your chair conformational structures can be perfect. 

Write a mechanism using sodium ethoxide in ethanol for the epimerization of cw-decalone to rra r-decalone. Draw chair conformational structures that show why frawr-decalone is more stable than molecular models of cis- and rra r-decalone. 

In the space provided on the Report Sheet (2e), draw the structure of cyclohexane in the chair conformation with all 12 hydrogens attached. Label all the axial hydrogens, Ha, and all the equatorial hydrogens, He. How many hydrogens are labeled Ha (2f) How many hydrogens are labeled He (2g) ... 

Draw the structural formula of aVl-[(R)-sec-butyl]-2-methylcyclohexane in its lowest energy chair conformation. How many isomers of this compound are there ... 

Draw the structural formula of 2,2-dichloro-l,l-difluoro-4,4-dimethylcyclo-hexane as a Newman projection formula viewed along the C1-C2 and C5-C4 bonds. Assume that the compound adopts a chair conformation. 

Which are the epimers of (2 ,4a ,8a )-decahydronaphthalen-2-ol Draw their structural formulae in the chair conformation. 

We can draw two nonsuperimposable mirror images of the most stable chair conformation of trans-1,2-dibromocyclohexane with both bromines equatorial. These structures cannot interconvert by ring-flips or other rotations about bonds, however. They are mirror-image isomers enantiomers. 

Q Draw and identify the structures of glucose, its anomers, and its epimers, as Fischer projections and as chair conformations. 

Learn to draw glucose, both in the Fischer projection and in the chair conformation (all substituents equatorial). Draw other pyranoses by noticing the differences from glucose and changing the glucose structure as needed. 

The simplest way to draw Haworth structures for these two sugars is to draw the chair conformations and then draw the flat rings with the same substituents in the up and down positions. For practice, however, let s lay down the Fischer projection for galactose. You should follow along with your molecular models. 

Draw the Fischer projections and the chair conformations of the anomers and epimers of glucose from memory. Identify and name these sugars based on how they differ from the structure of glucose. Problems 23-52 and 53... 

Draw the structures (using chair conformations of pyranoses) of the following disaccharides. 

The six-member glucose ring structure is not a flat ring. Like cyclohexane, it can exist in the chair conformation. Build models of the chair conformation of a- and (3-D-glucose. Draw each of these structures. Which would you predict to be the more stable isomer Explain your reasoning. 

The reaction involves a secondary substrate and a basic nucleophile elimination should predominate. Because cthoxide is a strong base, the E2 pathway is followed. The structure of the product is predictable because of the preference for anti elimination. Draw a chair conformation thtit places the leaving group (Cl) in an axial position. 

We draw ring structures as if the rings are flat, i.e., as if all the carbon atoms of the ring lie in the same plane. This is approximately correct for the 3-, 4-, and 5-membered rings. It is incorrect for the 6-membered and larger-sized rings which exist in a puckered, nonplanar shape. The 6-membered cyclohexane ring exists in the shape referred to as the chair conformation ... 

Draw the structure of ambroxol in the alternative chair conformation. Which of the two conformations is more stable ... 

The Te(Ses)2 ion contains two Se2] bidentate ligands coordinated to a square planar tellurium centre, (i) What is the oxidation state of Te in Te(Ses)2 (ii) Each TeSe -ring has a chair-conformation. Draw the structure of Te(Ses)2, given that the Te atom lies on an inversion centre. 

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