Hetero [4 + 2] Cycloadditions of (Trialkylsilyl)vinylketenes. Synthesis of α,β-Unsaturated δ-Valerolactones and -Lactams
作者:Dawn M. Bennett、Iwao Okamoto、Rick L. Danheiser
DOI:10.1021/ol9907217
日期:1999.8.1
[formula: see text] HeteroDiels-Alderreactions of (trialkylsilyl)vinylketenes (TAS-vinylketenes) with carbonyl and imino dienophiles are described. TAS-vinylketenes participate as electron-rich dienes in [4 + 2] cycloadditions with diethyl ketomalonate to afford alpha,beta-unsaturated delta-valerolactones in good yield. Nonenolizable N-alkyl- and N-(trimethylsilyl)imines combine with TAS-vinylketenes