Intramolecular Diels-Alder cycloadduct 10 was converted to the Stemona alkaloid stenine (1) via a reaction sequence that features a Curtius rearrangement (12 --> 13), Eschenmoser-Claisen rearrangement (19 --> 20) and stereoselective free radical allylation (4 --> 21).
Intramolecular Diels-Alder cycloadduct 10 was converted to the Stemona alkaloid stenine (1) via a reaction sequence that features a Curtius rearrangement (12 --> 13), Eschenmoser-Claisen rearrangement (19 --> 20) and stereoselective free radical allylation (4 --> 21).