41 数種のインドールアルカロイドの全合成

抄録

Some indole alkaloids have been synthesised by three methods; step by step synthesis, biomimetic type synthesis and retro mass spectral pattern synthesis. 4,6-Dimethoxycarbonyl-2-pyridone was converted into indolo[1,2-b]quinolin-9(11H)-one-7-carboxylic acid, whose methylation at C_8 with CH_2N_2, followed by conversion of methoxycarbonyl group into α-hydroxypropyl residue, gave mappicine. From a hypothesis that angustine would be biosynthesised from tryptophan and secologanin, angustine was synthesised by two routes from gentianine analogs which would be biogenetic equivalents to secologanin. On the basis of mass spectral fragmentation pattern of olivacine and yohimbine the former alkaloids could be synthesised from indole and 3,4-dibromomethyl-2-methylpyridine, and yohimbine from indolo-[2,3-a]quinolizin-2-one and 3-oxo-4-pentenoate. Moreover, the synthetic approach to the latter alkaloid by retro mass spectral pattern synthesis is also described.