1,7-acetal carbon rearrangement via 1,5-hydride transfer in an oxocanyl carbenium ion. Conversion of O-(5-hexenyl)-Se,O-heteroacetals or O,O-acetals into 7-oxohexanols or 7-oxohexyl chlorides)

Oxacyclooctyl (oxocanyl) carbenium ions generated by treatment of O-(5-hexenyl)-Se,O-heteroacetals or O,O-acetals with SnCl4 underwent intramolecular 1,5-hydride transfer, and the α-oxy carbenium ions newly formed were hydrolyzed to give the 7-oxohexanols or 7-oxohexyl chlorides in good yields. Various O-(5-hexenyl)-Se,O-heteroacetals or O,O-acetals were converted into 7-oxohexanols or 7-oxohexyl chlorides.