Gauche effect

Molecular-structural phenomenon

In the study of conformational isomerism, the gauche effect is an atypical situation where a gauche conformation (groups separated by a torsion angle of approximately 60°) is more stable than the anti conformation (180°). There are both steric and electronic effects that affect the relative stability of conformers. Ordinarily, steric effects predominate to place large substituents far from each other.

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