RESUMEN
A stereospecific Mizoroki-Heck cross-coupling of differently substituted glycals with haloarenes resulting in the exclusive formation of either α- or ß-aryl-C-glycosides depending solely on the configuration at C3 was achieved. The reaction was easy to set up because no specific precautions were required concerning moisture or oxygen, and it proceeded by a chirality transfer from C3 to C1. After optimization of cross-coupling conditions, various prepared glycals (7â examples) and arenes (10â examples) were tested, leading stereospecifically to the corresponding aryl-C-glycosides with a carbonyl group at C3, thus opening up new horizons for the total synthesis of glycosylated natural products.
RESUMEN
An efficient access for the synthesis of pluramycinones is described. Total syntheses of racemic γ-indomycinone and kidamycinone were achieved by means of two Diels-Alder reactions. A first Diels-Alder condensation followed by a Stille cross-coupling is used for the elaboration of the desired substituted dienes which will be involved in the second pericyclic reaction with juglone to construct the tetracyclic core of pluramycinones.