Concise total synthesis of (+/-)-salinosporamide A, (+/-)-cinnabaramide A, and derivatives via a bis-cyclization process: implications for a biosynthetic pathway?
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.
Ma
Gil
G
Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.
Nguyen
Henry
H
Romo
Daniel
D
D003116:Color; D007783:Lactones / Q000138:chemical synthesis*; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis*
D007783:Lactones; D011758:Pyrroles; C521217:cinnabaramide A; C475865:marizomib