Stereocontrolled Synthesis of Pseurotin A.

We report synthesis of two diastereomeric structures previously proposed for the complex secondary metabolite pseurotin A. Both structures were accessed from the same building blocks taking advantage of a stereodivergent nickel(II)-diamine-catalyzed 1,4-addition of a chiral 2-alkoxycarbonyl-3(2)-furanone. Late-stage Csp-Csp cross-coupling of a highly functionalized bromoalkyne featured in the pseurotin A side-chain assembly. The work supports the 2016 stereochemical revision of pseurotin A and represents the first chemical synthesis of this natural product.