Stable Nitrones From 17-Beta-Hydroxylamine Derivatives Of 8-Beta-Estrone And 8-Alpha-Estrone

17β-Hydroxylamine derivatives of 8β and 8α-estrone can be obtained by reduction of the corresponding oximes with diborane or NaCNBH 3 . The products can be converted easily and reversibly to nitrones by addition of aldehydes or ketones. The nitrones are more stable than the corresponding hydroxylamines, and may be used as protecting groups.