Hypervalent-iodine induced quasi-Favorskii C-ring contraction of 12-oxosteroids: A shortcut to C-norsteroids

[Display omitted] ► Treatment of 12-oxosteroids with PhI(AcO)2/KOH in CH3OH led to C-norsteroids. ► The observed Favorskii rearrangement follows the semibenzylic pathway. ► Hydroxyl groups or double bonds do not interfere with the observed reaction. Treatment of 12-oxosteroids with PhI(OAc)2 and KOH in refluxing methanol triggers a quasi-Favorskii C-ring contraction leading to the corresponding 11α-alcoxycarbonyl-C-norsteroids in moderate yields. This constitutes the first one-step synthetic alternative to C-norsteroids starting from 12-oxosteroids.