Sonochemically assisted 2,3-dideoxygenation and skeletal rearrangement of ecdysteroid derivatives

•Effectiveness of ultrasound in ecdysteroid 2,3-dideoxygenation was demonstrated.•Semipinacol rearrangement was observed in the case of 2,3-dimesyloxypoststerone.•2,3-Didesoxy-Δ2(3)-poststerone and its (8R)-13(14 → 8)-abeo-isomer were synthesized.•The method could be utilized for synthesis of rare naturally occurring abeo-ecdysteroids. Sonochemical 2,3-dideoxygenation of ecdysteroids with the Δ 2(3)-bond generation and activation of the C–C bonds of the steroid core in the poststerone derivatives, that causes the skeletal rearrangement have been carried out for the first time. Thus, the ultrasonically assisted reaction of 2,3-dimesyloxy derivatives of ecdysteroids with the NaI-Zn-DMF system gives rise to their 2,3-dideoxy-Δ2(3)-analogues with yields 70–92%. In the case of 2,3-dimesyloxypoststerone as the initial ecdysteroid substrate the reaction is accompanied by the activation of the allyl moiety and semipinacol rearrangement, resulting in the C13–C14 bond migration with C/D rings contraction/expansion and providing novel short chain (8R)-13(14 → 8)-abeo-isomer.