Abstract β-Alkoxyalkylidenemalonates undergo tandem radical addition− cyclization reactions to provide oxacycles of different ring sizes in good chemical efficiency. A variety of nucleophilic radicals participate in the addition− cyclization reactions, and the reaction requires the use of lanthanide triflates as Lewis acids. Compound 9 gave the 5-exo cyclization product 13 in 80% yield and greater than 50: 1 diastereoselectivity favoring the ...
