RESUMO
We report a concise synthesis of the naturally occurring protein synthesis inhibitor (+)-actinobolin (1). The densely functionalized and stereochemically complex molecular structure of 1 was assembled from (-)-quinic acid, L-threonine, and L-alanine as the principal components. Our route is based around a convergent strategy that features conjugate addition of an α-amino radical in the key fragment-coupling step. The dramatically simplified synthesis of (+)-actinobolin proceeding in 9 steps with 18 % overall yield has practical implications for analog preparation, as demonstrated herein.
Assuntos
Piranos , Estrutura Molecular , EstereoisomerismoRESUMO
We report synthesis of two diastereomeric structures previously proposed for the complex secondary metabolite pseurotin A2. 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(2H)-furanone. Late-stage Csp-Csp3 cross-coupling of a highly functionalized bromoalkyne featured in the pseurotin A2 side-chain assembly. The work supports the 2016 stereochemical revision of pseurotin A2 and represents the first chemical synthesis of this natural product.