Highly Stereoselective Synthesis of Biologically Active Conjugated Polyene Compounds

1.水稻植株对稻瘟病的防御物质合成。稻瘟病防治是日本的一项重要工程。1984年，我们合成了水稻中抗稻瘟病的自我防御物质--二吗啉甲酯(1)及其类似物。1985年，叔丁基壳聚糖和叔丁基(9E，11E，15Z)-13hydroxy-9，11，15-octadecatrienoate的合成方法建立。这些化合物对稻瘟病均无生物活性。看来，为了表现生物活性，酯类化合物应该转化为羧酸。尽管合成白蚁跟踪信息素(3Z，6Z，8E)-3，6，8-十二碳三烯-1-01的尝试以失败告终，但我们发现了一种新的合成2，5-二取代呋喃和硒的方法，该方法是在苯的回流温度下用二氧化硒氧化2，4-烷二烯酸酯。这是非常有趣的，因为在如此温和的条件下由双烯合成呋喃的报道从未见过。十八碳五烯酸的合成。第(1)节合成的化合物对果蝇的杀虫效果较弱，但实际效果并不理想。

1. Synthesis of self defensive substances in rice plant against rice blast disease. Protection of rice blast disease is one of important projects in Japan. In 1984, we could synthesize the methyl ester of dimorphecolic acid (1), the self defensive substance in rice plant against rice blast disease, and its analogs. In 1985, the synthesis of tert-butyl coriolate and tert-butyl (9E,11E,15Z)-13hydroxy-9,11,15-octadecatrienoate was established. These compounds showed no biological activity against rice blast disease. It seems that the esters should be converted to carboxylic acid for the manifestation of biological activity.2. Although the attempts to synthesize termite trail-following pheromone, (3Z,6Z,8E)-3,6,8-dodecatrien-1-01 resulted in failure, we found a new and novel synthetic method of 2,5-disubstituted furans and selenophenes via oxidation of 2,4-alkadienoic ester with selenium dioxide at the reflux temperature of benzene. It is very interesting because synthesis of furans from dienes under such a mild condition has never been reported.3. Synthesis of octadecapolyenoic acid. Insecticidal test of compounds prepared in section (1) to drosophilae showed weak effectiveness, but it is not efficient practically.