S. Mizukami et al., A NOVEL MICHAEL REACTION OF SILYL ENOL ETHERS VIA HETERO-DIELS-ALDER REACTION WITH ALKYLIDENE-MELDRUMS ACID, Tetrahedron letters, 34(46), 1993, pp. 7437-7440
Alkylidene Meldrum's acid easily reacted with silyl enol ethers withou
t any catalyst to afford hetero Diels-Alder adducts which could be qua
ntitatively hydrolyzed to obtain Michael adducts in good yields. The M
ichael adducts could be obtained diastereoselectively and could be con
verted to corresponding delta-ketoesters quantitatively.