The first total synthesis of penostatin B has been accomplished by using a highly diastereoselective Pauson-Khand reaction and an efficient relay ring-closing metathesis for the construction of the basic carbon skeleton of the natural product as the key steps.
Asymmetric Total Syntheses of (+)-Penostatins A and C
Penostatins A and C are cytotoxic natural products that show promising selective inhibitory activity against PTP1B. Here the first asymmetric total syntheses of (+)-penostatins A and C are reported. Our strategy features (i) a new method for the synthesis of 6-alkyl-3-hydroxy-2-pyrones, (ii) a cascade involving the intramolecular Diels-Alder reaction of 2-pyrone and a retro-hetero-Diels-Alder (decarboxylation) reaction, (iii) Ando-Horner-Wadsworth-Emmons olefination/lactonization, and (iv) selenoxide elimination. Our study confirmed the absolute configurations of penostatins A and C and laid the groundwork for further bioactivity studies.
Wang, Jian,Márquez-Cadena, Miguel Adrián,Tong, Rongbiao
Absolute stereostructures of novel cytotoxic metabolites, penostatins A- E, from a Penicillium species separated from an Enteromorpha alga
Penostatins A - E have been isolated from a strain of Penicillium sp. originally separated from the marine alga Enteromorpha intestinalis, and their absolute stereostructures and confirmations have been established on the basis of spectral analyses and so