Total synthesis of ascospiroketal a through a Ag(I) -promoted cyclization cascade.
The total synthesis of four candidate stereostructures for the marine octaketide ascospiroketal A have been achieved. These concise and highly stereocontrolled syntheses feature a unique Ag(I) -promoted cyclization cascade involving an oxetanyl ketochlorohydrin to access the entire tricyclic core of the natural product in one step. These syntheses also establish the full stereochemistry for the ascospiroketal natural products.
Department of Chemistry, Simon Fraser University, Burnaby, British Columbia (Canada).
Stanley
S
Chang
Soo
S
Hur
Robert
R
Britton
D001688:Biological Products / Q000138:chemical synthesis*; D002384:Catalysis; D003500:Cyclization; D004988:Ethers, Cyclic / Q000138:chemical synthesis*; D012834:Silver / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis*; D013237:Stereoisomerism
D001688:Biological Products; D004988:Ethers, Cyclic; D013141:Spiro Compounds; C518010:ascospiroketal A; D012834:Silver
natural products; polyketides; stereochemical assignment; tandem cyclization; total synthesis