Ring cleavage of indolo[2,3-a]quinolizidine 4 to an octahydroazecino[5, 4-b]indole system, followed by introduction of a cyano substituent and double transannular cyclization gives (±)-deethylibophyllidine.
吲哚[2,3-a]喹诺里西啶4的环裂解生成八氢阿泽西诺[5,4-b]
吲哚体系,随后引入
氰基取代基和双跨环关环反应得到(±)-去乙基利索非啶。