Abstract
The first total synthesis of two herbicidal natural products bacilosarcins A and B, the former of which incorporates a totally unprecedented heterobicyclic ring system and the latter contains a very rare heterecyclic structural motif, has been accomplished. The irregular ring systems in bacilosarcins A and B were constructed in very simple manners by means of an Amadori–type N–alkylation reaction as well as by taking advantage of the thermodynamic stability of the targeted rings. The total synthesis of PM–94128 and Y–05460M–A, cytotoxic natural products of microbial origin, has also been accomplished by a concise nine–step sequence from L–leucine and L–valine, respectively. The first synthesis of Y–05460M–A enabled its stereochemical determination.
