Solanum alkaloids. XVIII. Utilization of solasodine for the preparation of nitrogen analogues of ecdysones

Abstract

Solasodine (spirosol-5-en-3β-01) (1) has been converted into (20S,22R,25R)-26-acetylamino-2β,3β,14α- trihydroxy-5β-furost-7-en-6-one (41), a compound bearing ecdysone functionality in the steroidal nucleus aud retaining the N-atom in the side chain. The route involves dehalogenation of the bromohydrin (19), formed by treatment of N,O-diacetylsolasodine (6) with N-bromoacetamide and perchloric acid as catalyst. The 2β-, 3β- and 14α-hydroxy groups are introduced by Woodward-Pr�vost and selenium dioxide oxidations, respectively.