Synthesis of spongistatin 2 employing a new route to the EF fragmentElectronic supplementary information (ESI) available. See DOI: 10.1039/c3sc50304f

An improved route to the EF fragment of the spongistatins has been developed and employed in a synthesis of spongistatin 2. The C48-C51 diene side chain, which lacks the chlorine substituent present in spongistatin 1, presented some compatibility issues during target assembly. These were overcome by implementing a late stage Stille cross coupling to construct the diene portion of the natural product. An improved route to the EF fragment of the spongistatins has been developed and employed in a synthesis of spongistatin 2.