A convergent strategy for the pamamycin macrodiolides: Total synthesis of pamamycin-607, pamamycin-593, and pamamycin-621D precursors

Abstract

A convergent total synthesis of pamamycin-607 (1), isolated from Streptomyces alboniger, was achieved by an E-Z isomerization of a tetrahydrofuran alkylidene and a regio- and diastereoselective solvent-dependent cyclo-C6H11BCl/Et3N-mediated aldol reaction as the key steps. The second key step was extended to other ketones, opening the route to new pamamycin macrodiolides, for example, pamamycin-593 and pamamycin-621D. (Figure Presented) © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.