Construction of the septahydroxylated ABC-ring system of dihydro-β-agarofurans: application of 6-exo-dig radical cyclization. Issue 29 (27th March 2017)

• Record Type: Journal Article
• Authors: Fujisawa, Hiroki; Ishiyama, Tomochika; Urabe, Daisuke; Inoue, Masayuki
• Is Part Of: Chemical communications. Volume 53:Issue 29(2017)
• Page Start: 4073
• Page End: 4076
• Publication Date: 2017-03-27
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c7cc00507e
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : The intricate tricyclic system of highly oxygenated dihydro-β-agarofurans was constructed by utilizing 6- exo-dig radical cyclization as a key transformation. Abstract : A synthetic route to the septahydroxylated ABC-ring system of dihydro-β-agarofurans was established. The B-ring was formed by a base-promoted diastereoselective Diels–Alder reaction between 3-hydroxy-2-pyrone and ad -glyceraldehyde-derived dienophile, while the C-ring was cyclized by PhSeCl-mediated etherification. The remaining A-ring was constructed via a 6- exo-dig radical reaction. Selective transformations gave rise to the ABC-ring system1 with nine contiguous stereocenters. The thus obtained1 corresponded to the enantiomer of the densely oxygenated core structure of dihydro-β-agarofurans.