Header menu link for other important links
Chemoselectivity in the Michael Addition of Silyl Enol Ethers in Lithium Perchlorate-Diethyl Ether Medium. Evidence for Facile Silyl Group Transfer to Michael Acceptors
Vijaya Geetha Saraswathy,
Published in
Volume: 60
Issue: 16
Pages: 5024 - 5028
The silyl enol ethers from cyclohexanone and cyclopentanone underwent efficient 1,4-addition to β-nitro- and β,β-dicyanostyrenes in 5 M lithium perchlorate/diethyl ether (LPDE) at ambient temperature to give the corresponding Michael adducts in good yields and with moderate stereoselectivity. The reaction was found to be highly chemoselective in that α,β-unsaturated carbonyl compounds failed to undergo Michael addition with the silyl enol ethers under identical conditions. The experimental evidence suggests that the mechanism involves transfer of the silyl group from the silyl enol ether to the Michael acceptor. The silyl enol ethers reacted with p-benzoquinone in 5 M LPDE to give benzofuran derivatives in good yields. Reaction with chloranil yielded the corresponding O-alkylated products while with DDQ, the corresponding C-alkylated products were obtained in excellent yields and with high regio- and stereoselectivities. © 1995, American Chemical Society. All rights reserved.
About the journal
JournalJournal of Organic Chemistry
Open AccessNo