title: Concise total synthesis of (+/-)-salinosporamide A, (+/-)-cinnabaramide A, and derivatives via a bis-cyclization process: implications for a biosynthetic pathway?
abstract: 4-Alkylidene-beta-lactones (hetero ketene dimers) and alpha-amino acids are useful precursors for total syntheses of the beta-lactone-containing proteasome inhibitors salinosporamide A, cinnabaramide A, and derivatives. A key step is a nucleophile-promoted, bis-cyclization of keto acids that simultaneously generates the gamma-lactam and beta-lactone of these natural products. This reaction sequence may have implications for the biosynthesis of these natural products.
authors.affiliation: Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.
authors.forename: Gil
authors.initials: G
authors.lastname: Ma
authors.forename: Henry
authors.initials: H
authors.lastname: Nguyen
authors.forename: Daniel
authors.initials: D
authors.lastname: Romo
mesh_terms: D003116:Color; D007783:Lactones / Q000138:chemical synthesis*; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis*
chemical_list: D007783:Lactones; D011758:Pyrroles; C521217:cinnabaramide A; C475865:marizomib