Rearrangements in methanolysis of bis(2-bromoalkyl)selenides

Addition of selenium dibromide to 1-hexene, 1-octene, and allylic ethers occurs through the formation of intermediate kinetic anti-Markovnikov adducts that further transform into more thermodynamically stable Markovnikov adducts presumably via seleniranium intermediates. The methanolysis of both Markovnikov and anti-Markovnikov adducts leads to the formation of the same products in approximately the same ratio thus showing that the reaction proceeds through seleniranium intermediates.