Structural determination of oleanane-28,13β-olide and taraxerane-28,14β-olide fluorolactonization products from the reaction of oleanolic acid with Selectfluor™.

The X-ray crystal structure data of 12-α-fluoro-3β-hy­droxy­olean-28,13β-olide methanol hemisolvate, 2C₃₀H₄₇FO₃·CH₃OH, (1), and 12-α-fluoro-3β-hy­droxy­taraxer-28,14β-olide methanol hemisolvate, 2C₃₀H₄₇FO₃·CH₃OH, (2), are described. The fluoro­lactonization of oleanolic acid using SelectfluorTM 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. [ABSTRACT FROM AUTHOR]