Z and E how to tell the difference

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tobeylee_1C
Posts: 10
Joined: Sat Jul 23, 2016 3:00 am

Z and E how to tell the difference

Postby tobeylee_1C » Sun Mar 19, 2017 12:36 am

Im having a big confusion on how do you tell cis and trans when the line structure is shaped like monoterpenes. Anyone would care to explain a method to see if its Cis or Trans?

Anmol Dhaliwal 2C
Posts: 25
Joined: Wed Sep 21, 2016 2:57 pm

Re: Z and E how to tell the difference

Postby Anmol Dhaliwal 2C » Sun Mar 19, 2017 11:12 am

For those, look at the main chain of the carbons, then where the double bond is in the structure. Look at the two biggest molecules on the bond and identify if they are both going in the same direction (up or down). If they are, it would be a cis structure. If the two biggest molecules on the bond are in directions opposite to each other (for instance, if there is a substituent it could be facing out of the chain) so one is pointing to upward and the other downward, it would be a trans structure. Hope this helps!

Diana_Visco_1l
Posts: 31
Joined: Fri Jul 15, 2016 3:00 am

Re: Z and E how to tell the difference

Postby Diana_Visco_1l » Sun Mar 19, 2017 12:05 pm

Ensure that you are focussing on the "priority rules," in regards to breaking apart double bonds and giving precedence to elements with higher atomic #. Also looking at the line structure and where H atoms are bonded helps establish the geometry and provides a visual representation of where molecules are situation around bonds.


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