Describe the differences between the Hoffmann and Saytzeff rules.

The Hoffmann and Saytzeff rules are used to predict the major product in elimination reactions.

The Hoffmann rule states that when a hydrogen is removed from a quaternary ammonium salt, the least substituted alkene is formed. This is because the bulky groups on the quaternary ammonium salt hinder the formation of the more substituted alkene.

On the other hand, the Saytzeff rule states that when a hydrogen is removed from a tertiary amine, the more substituted alkene is formed. This is because the more substituted alkene is more stable due to the increased number of alkyl groups attached to the double bond.

A-Level Chemistry Tutor Summary: The Hoffmann and Saytzeff rules help predict the main product in elimination reactions. Hoffmann's rule suggests that with quaternary ammonium salts, the least substituted alkene is favoured due to steric hindrance. In contrast, Saytzeff's rule indicates that with tertiary amines, the more substituted alkene is preferred as it's more stable. These rules show how different structures influence the outcome of reactions.