Naturally occurring linear fused thiazoline-thiazole containing metabolites: total synthesis of (–)-didehydromirabazole A, a cytotoxic alkaloid from blue–green algae

A concise total synthesis of the thiazoline-thiazole containing metabolite didehydromirabazole A 1 is described. The synthesis uses the unusual amino acid (R)-2-methylcysteine 20 in sequential cyclocondensations with imino ethers as key steps, viz22→32 and 37→38.