The reaction of 1-phenylselenocyclopropylmethanols with TsOH in methanol proceeded smoothly to afford the homoallylic ethers, ring-enlargement products, and ring-opening products depending upon the kind Of substituent oil the cyclopropane ring or a-carbon. Oil the other hand. in the case of the absence of methanol as nucleophile, 4H-selenochromene derivatives were obtained exclusively.