Structural determination of oleanane-28,13β-olide and taraxerane-28,14β-olide fluoro-lactonization products from the reaction of oleanolic acid with Selectfluor TM .
Megan A EadsforthLinghan KongGeorge F S WhiteheadIñigo J Vitórica-YrezábalRaymond T O'KeefeRichard A BryceRoger C WhiteheadPublished in: Acta crystallographica. Section E, Crystallographic communications (2024)
The X-ray crystal structure data of 12-α-fluoro-3β-hy-droxy-olean-28,13β-olide methanol hemisolvate, 2C 30 H 47 FO 3 ·CH 3 OH, ( 1 ), and 12-α-fluoro-3β-hy-droxy-taraxer-28,14β-olide methanol hemisolvate, 2C 30 H 47 FO 3 ·CH 3 OH, ( 2 ), are described. The fluoro-lactonization of oleanolic acid using Selectfluor TM yielded a mixture of the six-membered δ-lactone ( 1 ) and the unusual seven-membered γ-lactone ( 2 ) following a 1,2-shift of methyl C-27 from C-14 to C-13.