Oxidative Substitution Reactions of Organostannyl Compounds with Lead Tetraacetate. A Convenient Route to 5-Alkylidene-2(5H)-furanones

Abstract 5-Substituted 2-tributylstannylfurans which were synthesized by the reaction of corresponding 5-substituted 2-lithiofurans with tributylstannyl chloride, were treated with two equimolar amounts of lead tetraacetate at room temperature to give corresponding 5-substituted 5-acetoxy-2(5H)-furanones in good yields. The 5-acetoxy-2(5H)-furanone was heated at 80 °C in acetic acid-acetic anhydride containing a catalytic amount of concentrated sulfuric acid to give 5-alkylidene-2(5H)-furanone in moderate yield.