Regio- and stereoselective synthesis of gamma-alkylidenebutenolides by cyclization of dilithiated 1,3-dicarbonyl compounds with N,N '-dimethoxy-N,N '-dimethylethane-diamide
P. Langer et M. Stoll, Regio- and stereoselective synthesis of gamma-alkylidenebutenolides by cyclization of dilithiated 1,3-dicarbonyl compounds with N,N '-dimethoxy-N,N '-dimethylethane-diamide, ANGEW CHEM, 38(12), 1999, pp. 1803-1805