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Gauche effect in 2-fluoroethanol

  1. Oct 16, 2015 #1


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    Generally, anti confirmation is more stable. But in case of 2-fluoro ethanol and 1,2-difluoroethanol the gauche confirmation is more stable.

    It's given in March's advanced organic chemistry book that intramolecular Hydrogen bonding is not the correct reason for the stability. Wikipedia explains it using hyperconjugation, but I am not able to understand it. What is the actual reason for gauche effect?
  2. jcsd
  3. Oct 19, 2015 #2


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    In the gauche conformation, the CH and CF bonds are in anti-position. Hence you can draw a resonance structure H+ C=C F-. This is only possible if the two atoms are not perpendicular to the pi bonding plane.
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