α,β-Unsaturated diesters: radical acceptors in dialkylzinc-mediated tandem radical addition/aldol condensation. A straightforward synthesis of rac-nephrosteranic acid
作者:Samantha Bazin、Laurence Feray、Nicolas Vanthuyne、Didier Siri、Michèle P. Bertrand
DOI:10.1016/j.tet.2006.10.049
日期:2007.1
The sequence involving conjugate radical addition/aldol condensation/lactonization is a high yielding route to di- and tri-substituted γ-lactones starting from fumaric or maleic diesters. The reactions are mediated with dialkylzincs. The domino process relies on the ability of dialkylzinc to transform α-alkoxycarbonylalkyl radicals into zinc enolates. Compared to diethylzinc, dimethylzinc enables the