The oxygenation reaction of cholesteryl acetate 1 was examined with the Fe(III)(PA)(3)/O(2)/MeCN system using an electrochemical method. The constant potential technique gave mainly the 7-hydroxylated product stereoselectively, along with the 7-oxo product. This oxygenation system is mechanistically unique, requiring iron catalyst, dioxygen, and both cathode and anode.

Complexes. -Iron complexes of picolinic acid catalyze the stereoselective 7α-hydroxylation of cholesteryl acetate (I). Constant potential technique, cf. conditions A), yield better results than the constant current method. Fe(II) picolinate can also be used as catalyst. Stereoselective hydroxylation is also observed in the case of oleanolate (IV). -(OKAMOTO, I.; FUNAKI, W.; NAKAYA, K.; KOTANI, E.; TAKEYA*, T.; Chem. Pharm. Bull. 52 (2004) 6, 756-759; Showa Pharm. Univ., Machida, Tokyo 194, Japan; Eng.) -C. Oppel 46-181