Diene-transmissive hetero Diels-Alder reaction of 1,5-diphenyl-1,4-pentadien-3-one

The diene-transmissive hetero Diels-Alder reaction of 1,5-diphenyl-1,4-pent adien-3-one is described. Stereoselectivity of the inverse electron-demand Diels-Alder reaction of electron-rich vinyl ethers at the first stage was g reately affected by the nature of Lewis acid-catalysts: The ZnX2 (X=Cl, I)- , MgBr2- and Eu(fod)(3)-catalyzed reactions gave the corresponding endo-add ucts, whereas exo-adducts were formed in the GaBr3-, AlCl3-, and Et2AlCl-ca talyzed reactions. Tn the sequential Diels-Alder reaction initial cycloaddu cts readily reacted with electron-deficient dienophiles such as 1,2,4-triaz olinedions, tetracyanoethene, and maleimides to give the corresponding cros s-bis-cycloadducts.