Total Synthesis of Pericoannosin A

Abstract

The first total synthesis of pericoannosin A (1) containing 15 steps in the longest linear sequence with an overall yield of 5.5% is reported. The hybrid peptide-polyketide was isolated from the endophytic fungus Periconia sp. F-31 and bears a unique tricyclic core structure. The key steps are a glycolate aldol reaction and a Diels-Alder reaction utilizing an Evans auxiliary for controlling the stereochemistry. Furthermore, a late-stage equilibration was employed.

Synthesis of the C18-C27 fragment of georatusin

“…In the context of our program to establish synthetic access to various natural products [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] we focused on those featuring the 1,3-(poly)deoxypropionate motif. A structurally challenging example is the polyketide-peptide hybrid georatusin (1) which was isolated from the soil fungus Geomyces auratus in 2018 by Bode and coworkers.…”

Applications of the Horner–Wadsworth–Emmons Olefination in Modern Natural Product Synthesis

“…81 The new synthetic route included a HWE reaction to install the substituted olefin and required less number of steps with improved overall yield in comparison to the total synthesis of 12 described by Kalesse and co-workers in 2018. 82 In short, an asymmetric Diels-Alder reaction with 145 and isoprene 146 yielded α,β-unsaturated aldehyde, which was subjected to a Wittig reaction to give terminal alkene 147. The corresponding β-ketophosphonate 149 was obtained by treatment of 147 with an excess of lithiated ethyl ethylphosphonate 148 in 91% yield.…”

Towards the total synthesis of chondrochloren A: synthesis of the (Z)-enamide fragment

“…In the course of our program to provide synthetic access to biologically active natural products we targeted complex polyketides and depsipetides [1][2][3][4][5][6][7][8][9][10]. One particular group of compounds of particular focus in our research activities are natural products with enamide moieties [11].…”