Total Synthesis of (+)-Elacomine and (?)-Isoelacomine, Two Hitherto Unnamed Oxindole Alkaloids fromElaeagnus commutata
作者:Claudio Pellegrini、Michael Weber、Hans-J�rg Borschberg
DOI:10.1002/hlca.19960790116
日期:1996.2.7
Racemic elacomine ((±)-2), a hemiterpene spiro oxindole alkaloid from Elaeagnus commutata, was synthesized in five steps from 6-methoxytryptamine (19) in 16% overall yield (Scheme 3). The final oxidative rearrangement of the corresponding β-carboline precursor (±)-21 furnished isoelacomine ((±)-22) as a by-product (6% overall yield). A more elaborate route that started from L-tryptophan furnished (+)-2
外消旋可卡因((±)-2)是一种从Elaeagnus commutata合成的半萜烯螺形羟吲哚生物碱,由6个甲氧基色胺(19)分五步合成,总收率为16%(方案3)。相应的β-咔啉前体(±)-21的最终氧化重排提供了副产物异丁香碱((±)-22)(6%的总收率)。从L-色氨酸提供的(+)- 2和(-)- 22的光学纯度为76%(方案4)开始,这是一条更精细的路线,并确定了这些化合物的绝对构型。的根的生物碱含量的重新调查E. commutata 结果表明,可卡因和异可卡因均以外消旋形式自然存在。