EFFICIENT SYNTHESIS OF BIOACTIVE NATURAL PRODUCTS EMPLOYING PALLADIUM-CATALYZED CYCLOALKENYLATION AS A KEY STEP

本研究的目的是以钯催化环烷基酰化酶为关键步骤，研究四分体和C_<20>赤霉素等具有生物活性的天然产物的全合成。(1)抗肿瘤药物四方酮的合成研究作者利用钯催化的在反式羟基上具有烯丙基的交叉共轭硅烯醇醚的环烯化反应，成功地合成了四方酮的基本碳骨架。(2)植物调节激素C_<20>赤霉素的合成研究首先，以钯催化环烯基化为关键步骤，构建了由环[3.2.1]辛烷组成的CD环体系。在双环[3.2.1]-辛烷环化合物上引入二烯和亲二烯部分后，对其进行分子内Diels-Alder反应，得到所需的五环化合物为单一立体异构体。环化产物(-)- ga_ <112>的官能团操纵。

The aim of this research is to investigate total syntheses of bioactive natural products, such as quadron and C_<20> gibberellins, employing the palladium-catalyzed cycloalkenylaton developed by the author as a key step.(1) Synthetic Studies on Antitumor agent Quadrone SynthesisThe author has succeeded in synthesizing the basic carbon skeleton of quadrone using the palladium-catalyzed cyclolakenylation of the cross conjugated silyl enol ether possessing an allyl group at one of the angular position of the trans-hydrindane.(2) Synthetic Studies on Plant Regulator Hormone C_<20> Gibberellin SynthesisFirst of all, the CD ring system, bycyclo [3.2.1] octane, was constructed using the palladium-catalyzed cycloalkenylation as the first key steps. After introduction of the diene and dienophile parts on the bicyclo [3.2.1]-octane ring compound, the intramolecular Diels-Alder reaction of it was performed to give rise to the desired penta cyclic compound as a single stereoisomer. Functional group manipulation of the cyclization product furnished(-)-GA_<112>.