Synthesis of cyclic enol ethers from alkenyl-beta-dicarbonyl compounds.
In this work we describe the cyclofunctionalization of eleven differently substituted alkenyl-beta-dicarbonyl compounds, employing three electrophilic reagents, namely, iodine, p-methoxyphenyltellurium trichloride, and phenylselenenyl bromide. The reactions occur through the enolic form of the substrates, to afford the corresponding iodo-, telluro-, or selenocyclic enol ethers. Substrates bearing trisubstituted double bonds failed in reacting with the selenium and tellurium reagents. In general, beta-diketones reacted faster than beta-keto esters with the three studied electrophiles.
Ferraz
Helena M C
HM
Instituto de Química, Universidade de São Paulo, CEP 05508-900, Brazil. hmferraz@iq.usp.br
Sano
Myrian K
MK
Nunes
Marta R S
MR
Bianco
Graziela G
GG