When multiple products are possible, the favored product will be the one with the most substituted double bond according to Zaitsev's rule.
In the Boord olefin synthesis, one reaction of this type is the proposed mechanism for forming the intermediate Grignard reagent. One reaction of this type involves moving the hydride from the beta position of a ligand to the metal center. This type of reaction will usually be second order in the presence of a strong base, and will then require that the leaving group and the departing hydrogen be coplanar in order to allow rehybridization of p orbitals to form the new pi bond. When multiple products are possible, the favored product will be the one with the most substituted double bond according to Zaitsev's rule. It's not rearrangement, but well known ones include those named for Cope and Hoffman. For 10 points, name this type of reaction usually involving alkyl halides in which two substituents are removed from a molecule.
In the Boord olefin synthesis, one reaction of this type is the proposed mechanism for forming the intermediate Grignard reagent.
elimination reactions