Synthetic Studies of Betaenones and Its Related Compounds

植物病原真菌产生的生物活性物质的合成研究，对植物病原真菌的结构确证、构效关系研究、生物合成代谢中间体的提供以及生物活性天然产物的提供具有重要意义。甜菜烯酮是从甜菜茎点霉（Phoma betae）的培养滤液中分离得到的植物毒素。在生物起源上，β烯酮被推测是通过分子内Diels-Alder反应衍生的。茄吡喃酮是马铃薯早疫病链格孢菌（Alternaria solani）产生的植物毒素，是马铃薯早疫病的诱发剂。玉米二倍体毒素（Diplodiatoxin）是从感染玉米二倍体（Diplodia maydis）的玉米中分离出的一种真菌毒素，玉米二倍体病是非洲南部牛和羊的常见病。β烯酮C的首次合成已经完成。这一结果使得进一步研究相关化合物的构效关系和生物合成成为可能2。合成<plus-minus>了（±）-茄吡喃酮A，其结构得到了明确的确证。用全合成法确定了（+）-双棘毒素的立体化学。

The synthetic studies of biologically active compounds produced by phytopathogenic fungi are now useful for the structural confirmation, study of structure-activity relationship, suply of biosynthetic and metabolic intermediate and suply of bioactive natural products. Betaenones are phytotoxins isolated from culture filtrate of Phoma betae, causal fungus of leaf spot disease of sugar beet. On the biogenesis, betaenones are presumed to be derived through the intramolecular Diels-Alder reaction. Solanapyrones are phytotoxins of Alternaria solani, incitant of early blight disease on potato. Diplodiatoxin is a mycotoxin isolated from infected maize with Diplodia maydis which causes a well known disease, diplodiosis, among cattle and sheep in Southern Africa.Research achievements within two years are summarized as follows1. The first synthesis of betaenone C has been completed. This result has made possible to investigate further the structure-activity relationship and biosynthesis of the related compounds2. (<plus-minus>)-Solanapyrone A has been synthesized and the structure was unequivocally confirmig3. The stereochemistry of (+)-diplodiatoxin has been determined by the total synthesis.