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

Abstract
Solasodine (spirosol-5-en-3.beta.-ol) [a Solanum alkaloid] was converted into (20S,22R,25R)-26-acetylamino-2.beta.,3.beta.,14.alpha.-trihydroxy-5.beta.-furost-7-en-6-one, a compound bearing ecdysone functionality in the steroidal nucleus and retaining the N-atom in the side chain. The route involves dehalogenation of the bromohydrin, formed by treatment of N,O-diacetylsolasodine with N-bromoacetamide and perchloric acid as catalyst. The 2.beta.-, 3.beta.- and 14.alpha.-hydroxy groups are introduced by Woodward-Prevost and selenium dioxide oxidations, respectively.