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Unformatted text preview: Guidelines for drawing cyclohexanes in 3D: Convince yourself of the chair's appearance by using a model. Practice manipulating the chair using models--copy what you see on the model onto a page. Avoid trying to draw the chair in one continuous line--this can lead to dreadful diagrams! PART 1: The framework of the chair Step 1: Draw a shallow "V" The two tips should be at the same level The lines should be the same length Step 2: Draw 2 parallel lines All lines should be of equal length Step 3: Draw second "V" Blue lines must be parallel. Green lines must be parallel. Red lines must be parallel. PART 2: adding substituents imagine a horizontal plane. Anything above the plane is "up". Anything below the plane is "down". Step 1: Axial Substituents are vertical lines
H H H Red bonds are going down Blue bonds are going up Notice that axial bonds alternate up and down around the ring
H H H Step 2: Equatorial substituents are parallel to a bond in the ring
H H H H H H Red hydrogens are going down Blue hydrogens are going up All purple bonds are parallel to each other All green bonds are parallel to each other All black bonds are parallel to each other Notice that equatorial bonds alternatee up and down around the ring The complete picture
H H H H H H H H H H H H H H H H H H H H H H H H cyclohexane in 2D cyclohexane in 3D Common Errors in 3D cyclohexane drawing: Note: all of these errors can (and should) be verified with a model
H H H H H H The chair has been drawn with the middle bonds horizontal, so the upper points of the chair are not level. This means that the axial hydrogens can no longer be drawn vertically. H H H H H H The axial hydrogens have been drawn alternating up and down the the wrong carbons. This structure is impossible because none of the carbons can be tetrahedral. H HH H H H The red hydrogens have been drawn at the wrong angles - correctly drawn would have parallel lines with the blue bonds of the ring ...
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This note was uploaded on 07/21/2010 for the course SCIENCE CHM 1321 taught by Professor Ogilvie during the Winter '09 term at University of Ottawa.
- Winter '09
- Organic chemistry