The first total synthesis of tanzawaic acid A(GS-1302-3) is described. The stereocontrolled synthetic route allowes the absolute stereochemistry to be determined. One key transformation in the sequence involves a Stille coupling with a highly hindered aryl triflate. Examples and results of several coupling reactions are also included.
Synthesis of Five- and Six-Membered-Ring
Compounds by Environmentally Friendly Radical Cyclizations Using
Kolbe Electrolysis
作者:István Markó、Frédéric Lebreux、Ferdinando Buzzo
DOI:10.1055/s-0028-1083547
日期:——
Substituted carbocycles, tetrahydrofurans, and tetrahydropyrans can be efficiently obtained from omega-unsaturated carboxylic acids. Our methodology involves a Kolbe decarboxylation followed by in intramolecular radical cyclization and a radical-radical cross-coupling process.
The invention relates to Iejimalides having the following formula (I) in which a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p are simple or double bonds, the continuous lines representing at least one simple bond, the dotted lines representing a possible bond. A double bond can be present but it is not necessary, and provided that a continuous line is also present, or a simple bond can be present if no other line is represented; m=0-20 and n1-n18=1, 2. The bonds can be used as chemotherapeutic agents for treating cancer.