Palladium-Catalyzed Selective Acyloxylation Using Sodium Perborate as Oxidant
作者:Lukasz T. Pilarski、Pär G. Janson、Kálmán J. Szabó
DOI:10.1021/jo1024199
日期:2011.3.4
component of washing powders, was employed as an inexpensive and eco-friendly oxidant in the palladium-catalyzed C−H acyloxylation of alkenes in excellent regio- and stereochemistry. The reactions used anhydrides as acyloxy sources. The method applies to both terminal and internal alkenes, and even benzylic C−H oxidation.
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
Total synthesis of (±)-paracaseolide A and initial attempts at a Lewis acid mediated dimerization of its putative biosynthetic precursor
作者:David S. Giera、Christian B. W. Stark
DOI:10.1039/c3ra44590a
日期:——
A short (5 steps) and highly efficient (25% overall yield) synthesis of paracaseolide A is described. Crucial steps are an α-iodination of a butenolide, a Suzuki coupling and a thermal Diels–Alder reaction. In attempts at Lewis acid catalyzed [4 + 2]-cycloadditions a set of novel dimerization products of the proposed biosynthetic paracaseolide A precursor were produced.