New approaches in asymmetric synthesis using γ-alkoxybutenolides

The synthesis of a new class of auxiliary based chiral synthons, γ-alkoxy-2(5H)-furanones, is described. The multifunctional compounds enter a variety of asymmetric transformations leading to acyclic- and cyclic-products with up to four new stereogenic centers in a single operation with stereoselectivities exceeding 98%. Applications in new routes to an enantiomerically pure β-lactam and lignans are given