10.1021/acs.orglett.8b03940.s001 Ansgar Oberheide Ansgar Oberheide Sebastian Pflanze Sebastian Pflanze Pierre Stallforth Pierre Stallforth Hans-Dieter Arndt Hans-Dieter Arndt Solid-Phase-Based Total Synthesis and Stereochemical Assignment of the Cryptic Natural Product Aurantizolicin American Chemical Society 2019 building blocks stereochemical assignment Ile residue NMR comparison producer organism Streptomyces aurantiacus Wittig reaction Stereochemical Assignment product macrocycle solution synthesis polyazole cyclopeptide aurantizolicin Cryptic Natural Product Aurantizolicin solid-phase peptide synthesis 2019-01-11 20:47:44 Journal contribution https://acs.figshare.com/articles/journal_contribution/Solid-Phase-Based_Total_Synthesis_and_Stereochemical_Assignment_of_the_Cryptic_Natural_Product_Aurantizolicin/7579910 The total synthesis and stereochemical assignment of the polyazole cyclopeptide aurantizolicin was achieved by connecting the solution synthesis of building blocks with solid-phase peptide synthesis. Macrothiolactonization and an <i>aza</i>-Wittig reaction provided the natural product macrocycle in high yield as well as key stereoisomers. NMR comparison as well as isolation of the natural product from the producer organism Streptomyces aurantiacus confirmed the presence and sequence of one l-Ile and one d-<i>allo</i>-Ile residue in aurantizolicin.