Chair Structures Flashcards
How do all six-membered cyclic structures exist?
In the chair form
Do you need dashed lines for chair structures?
No
What does each ring carbon have?
One axial and one equatorial bond
How do the axial and equatorial bonds of ring carbons minimise steric hindrance?
The orientations of axial and equatorial bonds alternate either above or below the plane
How do you determine what is what in ring flipping?
The sides stay the same (right and left) Each branch will swap between axial and equatorial
How can you help yourself keep track of which carbon is which in ring flipping?
Number them
Show the energy coordinate diagram of cyclohexane’s ring flipping
Which is more stable: axial or equatorial orientation?
Equatorial
Why are axial orientations less stable than equatorial arrangements?
Due to 1-3-diaxial interactions
What are 1-3-Diaxial interactions?
Where atoms on carbons 1 and 3 are in eclipsed orientations and steric repulsion occurs between them
How are cis-trans isomers determined in chair structures?
cis – both branches on the same side (both down or both up)
trans – on the opposite sides (one up one down)
