Chalcogeno−Morita−Baylis−Hillman Reaction of Enones with Acetals: Simple α-Alkoxyalkylation of Enones

1-[2-(Methylsulfanyl)phenyl]prop-2-en-1-one (1) and the seleno congener (2) reacted with acetals 3 and 21 in the presence of BF3·Et2O to give α-alkoxyalkyl enones 4, 5 and 22, 23 in good yields. When the reaction mixtures were worked up with a saturated NaHCO3 solution instead of Et3N, onium salts 6 and 7 were obtained together with 4 and 5. Reactions with cyclic acetal 14 gave α-(β-hydroxyethoxy) enones 15 and 16 accompanied by dimeric products 17 and 18

Chalcogeno−Morita−Baylis−Hillman Reaction of Enones with Acetals: Simple α-Alkoxyalkylation of Enones

1-[2-(Methylsulfanyl)phenyl]prop-2-en-1-one (1) and the seleno congener (2) reacted with acetals 3 and 21 in the presence of BF3·Et2O to give α-alkoxyalkyl enones 4, 5 and 22, 23 in good yields. When the reaction mixtures were worked up with a saturated NaHCO3 solution instead of Et3N, onium salts 6 and 7 were obtained together with 4 and 5. Reactions with cyclic acetal 14 gave α-(β-hydroxyethoxy) enones 15 and 16 accompanied by dimeric products 17 and 18