Synthesis of the Natural Product Marthiapeptide A.

The first total synthesis of marthiapeptide A is reported. Two synthetic procedures are described: the first, which was unsuccessful, attempts to close the ring at position I, and the second, which was successful, closes the ring at position II. It appears that the first route was unsuccessful because it required cyclization next to the rigid thiazole moiety, whereas the second route closed next to the more flexible thiazoline ring.