# Total Synthesis of (+)-Malbrancheamide B Employing a Bioinspired Strategy

## TL;DR

This paper describes a new method for the total synthesis of the complex natural compound (+)-malbrancheamide B using a bioinspired approach.

## Contribution

The paper introduces a novel bioinspired synthetic strategy for assembling the complex structure of (+)-malbrancheamide B.

## Key findings

- A bioinspired diketopiperazine assembly was used as a key step in the synthesis.
- A stereoselective oxidative radical cyclization provided a three-dimensional bridged diketopiperazine precursor.
- An intramolecular Friedel–Crafts cyclization formed the hexacyclic skeleton of the target compound.

## Abstract

Prenylated indole alkaloids are a class of secondary
metabolites
isolated from various terrestrial and marine fungi. The common complex
structure, featuring a diazabicyclo[2.2.2]­octane scaffold fused to
a tetrahydrocarbazole unit, and the numerous biological activities
make these compounds attractive synthetic targets. In the present
work an asymmetric total synthesis of (+)-malbrancheamide B is reported.
Key steps are bioinspired diketopiperazine (DKP) assembly, a stereoselective
oxidative radical cyclization, which gives access to the three-dimensional
bridged diketopiperazine precursor and an intramolecular Friedel–Crafts
cyclization providing the hexacyclic skeleton of malbrancheamide B.