Beta-agostic interactions can promote one type of these reactions in catalytic hydrogenation reactions. Xanthate pyrolysis is practically irreversible thanks to the formation of stable carbonyl sulfide and thiol byproducts in a reaction of this type. Amines can be removed through exhaustive methylation followed by treatment with silver oxide in a reaction of this type named for (*) Hofmann. For bimolecular (-5[1])reactions of this type, an anti-periplanar arrangement of atoms is required. (10[1])The unimolecular form of this reaction has the same intermediates as SN1 reactions, so its products compete with substitution products. (10[1])For 10 points, name these reactions that can form pi bonds through E2 or E1 mechanisms. (10[1])■END■ (10[1])