Transannular Reductive Rearrangement of α‑Amino Ketones: Construction of Aza-tricyclic Frameworks of Several Alkaloids

Transannular reductive rearrangement of bridged cyclic α-amino ketones led to the aza-tricyclic frameworks azepinoindole, hydrolulolidine, and hydrojulolidine of the typical alkaloids of Stemona, Aspidosperma, and Lycopodium, respectively. This facile approach demonstrates the potential applicability of the Clemmensen–Clemo–Prelog–Leonard reductive rearrangement of tricyclic α-amino ketones for the aza-heterocycle synthesis.桥环α-氨基酮的跨环还原重排反应，可分别构建对应百部属、白坚木属、石松属典型生物碱所含的氮杂三环骨架：氮杂卓并吲哚(azepinoindole)、氢化卢洛利定(hydrolulolidine)以及氢化朱洛利定(hydrojulolidine)。该简便合成策略证实了三环α-氨基酮的克莱门森-克莱莫-普雷洛格-伦纳德还原重排反应在氮杂杂环合成中的潜在应用价值。