title: Synthesis of Cycloprodigiosin Identifies the Natural Isolate as a Scalemic Mixture.
abstract: The enantiomers of the natural product cycloprodigiosin were prepared using an expedient five-step synthetic sequence that takes advantage of a Schöllkopf-Barton-Zard (SBZ) pyrrole annulation with a chiral isocyanoacetate and a nitrocyclohexene derivative. Using chiral HPLC and X-ray crystallographic analyses of the synthetically prepared material and natural isolate (isolated from the marine bacterium Pseudoalteromonas rubra), naturally occurring cycloprodigiosin was determined to be a scalemic mixture occurring in an enantiomeric ratio of 83:17 (R)/(S) at C4'.
authors.affiliation: †Department of Chemistry, University of California, Berkeley, California 94720, United States.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Johnson
authors.affiliation: †Department of Chemistry, University of California, Berkeley, California 94720, United States.
authors.forename: Tristan
authors.initials: T
authors.lastname: de Rond
authors.affiliation: †Department of Chemistry, University of California, Berkeley, California 94720, United States.
authors.forename: Vincent N G
authors.initials: VN
authors.lastname: Lindsay
authors.affiliation: ‡Department of Chemical and Biomolecular Engineering, Department of Bioengineering, and QB3 Institute, University of California, Berkeley, California 94720, United States.|§Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, United States.|∥Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, California 94270, United States.
authors.forename: Jay D
authors.initials: JD
authors.lastname: Keasling
authors.affiliation: †Department of Chemistry, University of California, Berkeley, California 94720, United States.
authors.forename: Richmond
authors.initials: R
authors.lastname: Sarpong