Intramolecular cyclopropene-furan [2 + 4] cycloaddition followed by a cyclopropylcarbinyl rearrangement to synthesize the BCD rings of cortistatin A.
Synthesis of the BCD ring system of cortistatin A has been accomplished in 9 steps and 30% overall yield starting from commercially available 2-methylcyclopent-2-enone. Key transformations include the addition of cyclopropenyllithium 16 to aldehyde 15, an intramolecular cyclopropene-furan [2 + 4] cycloaddition leading to epimers 18/19, and a subsequent cyclopropylcarbinyl rearrangement to afford 24.
Magnus
Philip
P
Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-1167, USA. p.magnus@mail.utexas.edu
Littich
Ryan
R
D000818:Animals; D002384:Catalysis; D003500:Cyclization; D003517:Cyclopentanes / Q000737:chemistry*; D007546:Isoquinolines / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D011083:Polycyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D011161:Porifera / Q000737:chemistry; D013237:Stereoisomerism
C433947:2-methylcyclopentenone; D003517:Cyclopentanes; D007546:Isoquinolines; D011083:Polycyclic Compounds; C531521:cortistatin A