X-ray structure analysis of the title compound, C19H23NO4, showed an u
nexpected anti orientation for the 6-oxo-7-oximino function. After mol
ecular-mechanics calculations, the H atom of the 17-hydroxy moiety, wh
ich participates in a strong hydrogen bond formed in the crystalline s
tate, changed its orientation substantially. Some change in the confor
mation of ring. B was also observed.