title: Stereochemical assignment of the C1-C6 fragment of psymberin by synthesis and natural product degradation.
abstract: [reaction: see text] Psymberin is a sponge-derived natural product that shows striking selectivity as a cytotoxic agent. Conformational mobility has precluded stereochemical assignment for the acyl fragment of this molecule (psymberic acid) by NMR. Herein we report stereoselective syntheses of all four stereoisomers of psymberic acid. A comparison of the acid-mediated cyclization products of these compounds to the product of psymberin's acidic methanolysis showed the stereochemical configuration of this fragment to be 4S,5S.
authors.affiliation: Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Green
authors.forename: Jason C
authors.initials: JC
authors.lastname: Rech
authors.forename: Paul E
authors.initials: PE
authors.lastname: Floreancig
mesh_terms: D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D001688:Biological Products / Q000737:chemistry*; D002849:Chromatography, Gas; D003374:Coumarins; D015394:Molecular Structure; D011714:Pyrans / Q000138:chemical synthesis / Q000737:chemistry*; D011753:Pyrones / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000577:Amides; D000588:Amines; D001688:Biological Products; D003374:Coumarins; D011714:Pyrans; D011753:Pyrones; C498383:psymberin; C100127:pederin