Biomimetic Total Synthesis of Malbrancheamide and Malbrancheamide B

摘要

The biomimetic total syntheses of both malbrancheamide and malbrancheamide B are reported. The synthesis of the two mono-chloro species enabled the structure of malbrancheamide B to be unambiguously assigned. The syntheses each feature an intramolecular Diels-Alder reaction of a 5-hydroxypyrazin-2(1H)-one to construct the bicyclo[2.2.2]diazaoctane core, which has also been proposed as the biosynthetic route to these compounds.