The Thermal α-Substitution of Dimedone by Vinyl Ethers

Pyrolysis of a mixture of dimedone (1) and 1-methoxycyclohexene (2) led to formation of the enedione (3), which underwent both a Diels-Alder reaction with (2) to form the spiro compound (4), and reaction with oxygen to give the cyclic peroxide (5). The possibility of extending the initial reaction, which is thought to proceed by an ene mechanism, to some cyclic vinyl ethers has been examined.