Rearrangement of ent-7 alpha,18-diacetoxy-14 beta-mesyloxybeyer-15-ene (4) under several conditions gave 12(13-->14)-abeo compounds (5 or 7), on some occasions in high yield, which evolved to 12(13-->14),15(8-->17)-diabeo compounds in acidic medium, Structures of rearranged products were established principally with the aid of INADEQUATE and other 2D-nmr experiments.