Efficient total synthesis of bastadin 6, an anti-angiogenic brominated tyrosine-derived metabolite from marine sponge

An efficient total synthesis of bastadin 6 (1), a cyclic tetramer of brominated tyrosine derivatives from the marine sponge, lanthella basta, with selective anti-angiogenic activity, was accomplished. We developed a novel Ce(IV)-mediated oxidative coupling reaction of 2,6-dibromophenols to give the diaryl ether derivatives, the characteristic segment of 1. Condensation of two segments and subsequent intramolecular macrocyclization gave bastadin 6 (1) in nine steps, 26% overall yield. (c) 2005 Elsevier Ltd. All rights reserved.