A. Arnone et al., DIRECT OXYFUNCTIONALIZATION AT UNACTIVATED SITES - SYNTHESIS OF 5-BETA-HYDROXYSTEROIDS BY PERFLUORODIALKYLOXAZIRIDINES, Journal of organic chemistry, 59(19), 1994, pp. 5511-5513
By treatment with perfluoro-cis-2-n-butyl-3-n-propyloxaziridine 1a, 5
beta-steroids 2a-i (belonging to different classes, such as androstane
s, cholestanes, pregnanes, and cholanic acids) have been hydroxylated
in good yields and with complete site selectivity and stereoselectivit
y to corresponding 5 beta-hydroxy derivatives 3a-i independently from
the presence of halide, ketone, carboxylic acid, and ester moieties on
C-3, C-11, C-12, C-17, C-20, C-21, and C-24.