Gauche vs Anti

[Maggie Elgin 2A]

I am having difficulty deciding when to use anti or gauche? Could someone explain the difference between the two Newman projections?

[Emma_Green_2C]

Gauche is when the large atoms are staggered adjacent to each other (60 degrees) and anti is when the large atoms are opposite each other (180 degrees). Both are staggered but the names gauche and anti tell you the different energies of the conformations. Anti is the most stable (lowest energy) and gauche is less stable than anti but more stable than eclipsed.

[Cayla_Brooks_1I]

If a problem were asking you draw the most stable and least stable form, would there ever be a situation where Gauche is more stable than Anti?

[Nikhita_Jaaswal_2H]

No in the examples all given, anti is the most stable conformation

[Tycho_Meimban_2B]

Use Anti (180 degrees apart) for the most stable Newman projection, and use eclipsed for the least stable Newman projection.

Hope this helps!