Oxidative Rearrangement of 4-Hydroxy-2-cyclobutenone. A New Route to Highly Substituted Furanones from Squaric Acid
摘要:
4-Hydroxy-2-cyclobutenones, which were obtained by the reaction of diethyl squarate with an organolithium, reacted with lead tetraacetate (to generate an oxy radical) affording 5-acetoxy-2(5H)-furanones and 5-alkylidene-2(5H)-furanones. This type of rearrangement was realized in a simple four-membered cyclic alpha-ketol but not in the corresponding five-membered ring.