Cyclohexane drawing

It IS no accident that sections of our chair cyclohexane drawings resemble saw horse projections of staggered conformations of alkanes The same spatial relationships seen m alkanes carry over to substituents on a six membered ring In the structure... 

EXERCISE 6.30 Below you will see one chair conformation of a substituted cyclohexane. Draw the other chair (i.e., do a ring flip) ... 

Kodef polyester is formed by transesterification of dimethyl terephthalate with 1,4-di-(hydroxymethyl)cyclohexane. Draw the structure of Kodel . 

Kodel is a polymer of terephthalic acid and tra r-di-l,4-(hydroxymethyl)cyclohexane. Draw a representation of the polymer. 

For each of the following substituted cyclohexanes, draw the two possible chair conformations, label each substituent as axial or equatorial, and identify the more stable conformer. 

Alternatively, any or all three files for benzene, cyclohexene, and cyclohexane can be generated using the draw option of PCMODEL. Either way, the cyclohexene file is... 

The conformational features of six membered rings are fundamental to organic chemistry so it is essential that you have a clear understanding of the directional prop erties of axial and equatorial bonds and be able to represent them accurately Figure 3 17 offers some guidance on the drawing of chair cyclohexane rings... 

Practice drawing cyclohexane chairs oriented in either direction... 

Pr actice drawing cyclohexane chair s oriented in either dir ection. 

The easiest way to visualize chair cyclohexane is to build a molecular model. (In fact do it now.) Two-dimensional drawings like that in Figure 4.7 are useful, but there s no substitute for holding, twisting, and turning a three-dimensional model in your own hands. The chair conformation of cyclohexane can be drawn in three steps. 

Draw two parallel lines, slanted downward and slightly offset from each other. This means that four of the cyclohexane carbons lie in a plane. 

Figure 4.10 A procedure for drawing axial and equatorial bonds in chair cyclohexane.

Interactive to learn to draw and assess the stability of substituted cyclohexanes. 

Thomson NOV Click Organic Interactive to use an online palette to draw and interconvert cyclohexane structures. 

Drawing the Most Stable Conformation of a Substituted Cyclohexane... 

Norbornane has a conformationally locked boat cyclohexane ring (Section 4.5) in which carbons 1 and 4 are joined by an additional CH group. Note how, in drawing this structure, a break in the rear bond indicates that the vertical bond crosses in front of it. Making a molecular mode) is particularly helpful when trying to see the three-dimensionality of norbornane. 

Amantadine is an antiviral agent that is active against influenza A infection and against some strains of H5NX avian flu. Draw a three-dimensional representation of amantadine showing the chair cyclohexane rings. 

Atorvastatin, structure of, 105. 516 ATP (see Adenosine triphosphate) ATZ, see Anilinothiazolinone, 1031-1032 Aufbau principle. 6 Axial bonds (cyclohexane), 119 drawing, 120 Azide, amines from, 929 reduction of, 929 Azide synthesis, 929 Azo compound, 944 synthesis of, 944-945 uses of. 945... 

An interesting case of conformational analysis comes to play when we consider a six-membered ring (cyclohexane). There are many conformations that this compound can adopt. You will see them all in your textbook the chair, the boat, the twist-boat. The most stable conformation of cyclohexane is the chair. We call it a chair, because when you draw it, it looks like a chair ... 

Fig. 7.1 Symbolic drawings of cyclohexane chair and boat conformations in two dimensions using different line thickness and wedge symbols.

In considering the retrosynthetic analysis of juvabione, two factors draw special attention to the bond between C(4) and C(7). First, this bond establishes the stereochemistry of the molecule. The C(4) and C(7) carbons are stereogenic centers and their relative configuration determines the diastereomeric structure. In a stereocontrolled synthesis, it is necessary to establish the desired stereochemistry at C(4) and C(7). The C(4)-C(7) bond also connects the side chain to the cyclohexene ring. As a cyclohexane derivative is a logical candidate for one key intermediate, the C(4)-C(7) bond is a potential bond disconnection. 

Fig. 18. Top transition coordinates (with symmetry species) of conformational transition states of cyclohexane (top and side views). Hydrogen displacements are omitted. The displacement amplitudes given are towards the C2v-symmetric boat form, and towards >2-symmetric twist forms (from left), respectively. Inversion of these displacements leads to the chair and an equivalent T>2-form, respectively. Displacements of obscured atoms are given as open arrows, obscured displacements as an additional top. See Fig. 17 for perspective conformational drawings. Bottom pseudorotational normal coordinates (with symmetry species) of the Cs- and C2-symmetric transition states. The phases of the displacement amplitudes are chosen such that a mutual interconversion of both forms results. The two conformations are viewed down the CC-bonds around which the ring torsion angles - 7.3 and - 13.1° are calculated (Fig. 17). The displacement components perpendicular to the drawing plane are comparatively small. - See text for further details.

Figure 4.12 Representations of the chair conformation of cyclohexane (a) Carbon skeleton only (b) Carbon and hydrogen atoms (c) Line drawing (d) Space-filling model of cyclohexane. Notice that there are two types of hydrogen substituents—those that project obviously up or down (shown in red) and those that lie around the perimeter of the ring in more subtle up or down orientations (shown in black or gray). We shall discuss this further in Section 4.13.

Figure 4.16 (a) Carbon skeleton and (b) line drawing of the twist conformation of cyclohexane. 

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