Total synthesis of brasoside and littoralisone.
The first total syntheses of littoralisone (1) and brasoside (2) have been achieved in 13 overall steps. Both natural products are forged from a common intermediate which is rapidly assembled using organocatalytic technology, including a proline-catalyzed alpha-aminoxylation and a contra-thermodynamic intramolecular Michael addition. Application of the two-step carbohydrate synthesis technology has enabled to access a selectively substituted glucose derivative for use as an intramolecular cycloaddition tether. This synthesis culminates with an intramolecular [2+2] photocycloaddition that serves to support the proposed biosynthetic origins of 1 from 2.
Mangion
Ian K
IK
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
MacMillan
David W C
DW
D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis*; D011392:Proline / Q000737:chemistry; D032412:Verbena / Q000737:chemistry
D006027:Glycosides; D006576:Heterocyclic Compounds, 4 or More Rings; C500655:brasoside; C427482:littoralisone; D011392:Proline