Development of Synthetic Methods toward Biologically Active Compou

为了合成多种C-核苷，我们打算将D-核糖基和D-脱氧核糖基与含N的芳香族杂环结合。以二苯基二酰氧基硒、二酰氧基苯、四(三甲基硅基)硅烷和硫代异羟肟酸酯为自由基试剂，在光化学和热条件下对C-核苷的合成进行了考察，结果表明Barton反应适用于C-核苷的合成。因此，利用Barton反应合成了几种C-核苷。接下来，利用离子反应进行了C-核苷的合成：将典型的芳香杂环锂盐引入到苯基保护的D-核糖上，然后进行酸环化。

In order to synthesize many kinds of C-nucleosides, we intended to combine D-ribosyl and D-deoxyribosyl radicals with N-containing aromatic heterocycles. As the radical reagents, diphenylselenium diacyloxylate, (diacyloxyiodo)benzene, tetrakis(trimethylsilyl)silane, and thiohydroxamic acid ester known as the Barton reagent were examined under photochemical and thermal conditions.The result showed that the Barton reaction could be applicable for the C-nucleoside synthesis. Therefore several C-nucleosides were synthesized by employing the Barton reaction. The other reagents required the further investigation for the C-nucleoside synthesis.Next, the synthesis of C-nucleosides was performed by utilizing the ionic reaction : the lithium salt of typical aromatic heterocycles was introduced onto the benzyl-protected D-ribose followed by the acid-cyclization.