ORG CHEM HELP Newman Confirmations Help

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nike_victoria
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ORG CHEM HELP Newman Confirmations Help

Post by nike_victoria »

Help me please!

Recall that in the Newman projection of ethane, there are no substituents (non-hydrogens) on either carbon. As a result, there are only 2 conformations: Staggered and Eclipsed. For the Newman projection of propane, sighting along the C2-C3 bond, there is 1 substituent on the front carbon: a methyl group. This still results 2 conformations: Staggered and Eclipsed. In butane, sighting along the C2-C3 bond, there are now 2 methyl substituents with 1 on each carbon. This results in 4 possible conformations: Staggered-Anti, Staggered-Gauche, Eclipsed 1, and Eclipsed 2.

QUESTIONS:
1. What if there were more than 2 substituents?
2. Consider 2-fluorobutane, sighted along the C2-C3 bond. Name the substituents on C2 and C3. Draw all the different Newman conformations. Finally, rank them from most stable to least stable.
 
Thank you!
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ChenBeier
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Re: ORG CHEM HELP Newman Confirmations Help

Post by ChenBeier »

1. Depends if the substituents the same or different, then you got more isomers.
2. With the 2- Fluorbutane you get already R/S isomers.
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