Synthesis of 26-acetylamino analogs of cholesterol based on 16,22-diketone from O,N-diacetylsolasodine

Steroidal alkaloids

“…5-1 Triacetylpseudosolasodine (1 5a) furnished the methoxy-derivatives (15b) and ( 16) on brief treatment with iodine in methanol. Alternatively, on treatment with iodine in acetic acid, (1 5a) gave the diastereoisomeric 23-acetoxyderivatives (1%) together with the conjugated diene (17); in contrast, the epimeric pyrrolidines (18) were formed when (1 5a) was treated with iodine in dimethylformamide. l 6 The diketone (19) was prepared from N,O-diacetylsolasodine (1 1 b), and submitted to further transformations.…”