Biologically Active Substances by Use of Electrochemical Oxidation Associate Professor

内酰胺的阳极氧化在有机合成化学中具有重要的应用价值。我们已经报道了用电化学氧化法从4-羧基-2-叠氮啶酮合成4-乙酰氧基-2-叠氮啶酮的新方法。即以AcONa作为电解液存在于AcOH-CH_3CN中，以铂板为电极，在未分裂的电解槽中电解4-羧基-2-叠氮啶酮，得到高产率的4-乙酰氧基-2-叠氮啶酮。在此基础上，提出了一种合成噻霉素及其类似物的中间体- 3-羟基乙基-4-乙酰氧基-2-氮杂二酮的新方法，并实现了(+)-PS-5的正式全合成。该方法应用于γ -内酰胺的合成。对焦谷氨酸进行电解，得到2-乙酰氧基吡咯酮，产率较高。以类似的方法，从1a和1b得到化合物2a和2b。随后，在吡咯酮的2位上尝试了C-C键的形成。用TiCl_4处理由化合物5__电解得到的化合物6__，得到了收率较高的吲哚吡啶衍生物。由此，提出了以氮α位羧基内酰胺为原料，电解法合成双环内酰胺的新方法。

Anodic oxidation of lactoms was very useful for the synthetic organic chemistry. We have already reported the new synthetic method of 4-acetoxy-2-azatidinones from 4-carboxy-2-azetidinones by use of electrochemical oxidation. Namely, 4-carboxy-2-azatidinone was electrolyzed in an undivided cell using platinum plates as electrode in the presence of AcONa as electrolyte in AcOH-CH_3CN to give 4-acetoxy-2-azetidinone in high yield. Using this method, a new synthetic method of optically active 3-hydroxy-ethyl-4-acetoxy-2-azetidinone which was an intermediate for the synthesis of thienamycin and its analogues, was developed and a formal total synthesis of (+)-PS-5 was achieved. This method was applied for the synthesis of gamma-lactams. Pyroglutamic acid was electrolyzed to afford 2-acetoxy-pyrrolldone in good yield. In a similar manner, compounds2a and 2b were obtained from 1a and 1b. Subsequently, C-C bond formation at 2-position of pyrrolldone was tried. Compound 6__- which was obtained by electrolysis from compound 5__- was treated with TiCl_4 to provide indollzidine derivative in good yield. Thus, the new method for the synthesis of bicyclic lactams by electrolysis from lactams having carboxy group at alpha-position of nitrogen was developed.