Synthesis of southern (C1′-C11′) and eastern (C8-C18) fragments of pamamycin-607, an aerial mycelium-inducing substance of Streptomyces alboniger

Synthesis of the southern C1′-C11′ and eastern C8-C18 fragments of pamamycin-607, an aerial mycelium-inducing substance of Streptomyces alboniger, was achieved. The southern fragment was synthesized by using the Evans aldol reaction and cis-selective iodoetherification as the key steps in a 9.6% overall yield (7 steps). The eastern fragment was constructed via the Julia coupling reaction and cis-selective iodoetherification in a 3.0% overall yield (8 steps from the known epoxide).