Furanones are well known as basic components of natural products, some of which display a wide range of characteristic physiological properties. Transition-metal catalyzed transformations of propargyl compounds have been widely used for the construction of a variety of carbo- and heterocycles. Tamaru et al. reported the cyclization of O-propargyl carbamates afforded oxazolidinones. Herein, we report a one-step synthesis of 5-alkoxy-3(2H)-furanones 2 via a novel box-Pd(II) catalyzed carbonylative cascade reaction of propargyl carbamates 1. The reaction of 1 in the presence of [PhboxPd(tfa)2] (5 mol %) and p-benzoquinone (1.5 equiv.) in methanol under CO atmosphere (balloon) afforded 2 in 56-99 % yield. The first asymmetric version of this transformation is also discussed.
