Formation of 2-halomethylene-4-cyclopentene-1,3-diones and/or 2-halo-1,4-benzoquinones, total synthesis of methyl linderone and Wacker-type oxidation of aryl-substituted alkenes

We have discovered a practical general method for the preparation of diverse 2-halomethylene-4-cyclopentene-1,3-diones and/or 2-halo-1,4-benzoquinones. An in-depth study of the reactions of 4-(ethynyl)-4-hydroxy-2,3-substituted-2-cyclobuten-1-ones with N-bromo- or N-iodosuccinimide is described. This reaction was used in a short total synthesis of methyl linderone. Also, a series of facile, palladium catalyzed, direct, and regiospecific Wacker-type oxidations has been developed to yield various alpha-arylated ketones from aryl-substituted internal alkenes.