作者:David Din Belle、Arto Tolvanen、Mauri Lounasmaa
DOI:10.1016/0040-4020(96)00663-1
日期:1996.8
Total syntheses are described for seven tacamine-type indole alkaloids (1–7) found in Tabernaemontana eglandulosa. (±)-Tacamine (1), (±)-16-epitacamine (2), and (±)-apotacamine (3) were prepared from pentacyclic intermediates 18. Apotacamine (3) was also obtained from aldehyde 12via epimerization of 20-epiapotacamine (19) by the Polonovski-Potier reaction. Homologation of ester 13 led to 20-epitacamonine
总的合成描述了七种塔巴胺型吲哚生物碱(1–7),这些生物存在于Tabernaemontana eglandulosa中。从五环中间体18制备了(±)-塔卡明(1),(±)-16-依帕他敏(2)和(±)-阿帕他敏(3)。通过Polonovski-Potier反应,通过醛化20-表胺(19)也从醛12中获得了胺(3)。酯13的同系化产生20-依他卡莫宁(23),其类似地转化为(±)-他卡莫宁(4)。减少4给出了(±)-去甲氧甲氧基他胺5和6。醛11与三甲基甲硅烷基氰化物(TMSCN)反应,生成两个(±)-17-羟基塔卡蒙宁(7),发现其中两个带有轴向羟基的异构体(17β-OH)与天然化合物相同。最后,描述了制备(±)-19 S-羟基他胺(8)的尝试。作为该中间体,实现了吡啶生物碱5-(1'-羟乙基)烟酸酯甲基的新合成(34)。