Development of the Highly Efficient Methodology for the Construction of Medium-sized Cyclic Ethers and its Application to Polycyclic Ether Compounds.

1.一种合成中型环醚的催化剂和循环体系的开发我们用Eu（fod）_3催化羟基环氧化物环化合成中型环醚。为了从原子经济的角度发展成有效的方法，对该方法的催化和循环系统进行了研究。为此，使用离子液体/有机溶剂和氟溶剂/有机溶剂体系。预期催化量的刘易斯酸在该条件下浓缩并加速反应。然而，这些尝试都是徒劳的。研究了刘易斯酸对该反应的催化作用，发现Y（hfa）_3是一种有效的刘易斯酸，但它不适用于催化.建立了高效立体选择性构建多环醚骨架的方法，并利用上述方法研究了多环醚骨架的立体选择性构建。 ...更多信息 logy.1）7元环醚的延伸：将包括环氧部分的膦酸酯设定为手性合成子。使用该试剂的一系列Horner-Emmons型反应，由相邻环氧基团的立体化学诱导的羰基的反选择性还原提供了具有所需的羟基和环氧基团的立体化学的前体。（2）8元和9元环醚的扩链：以（+）-甘露醇衍生的手性二环氧化物为手性合成子，合成了8元和9元环醚的扩链产物。应用Yamaguchi的方案将炔阴离子添加到二环氧化物中，得到具有所需的羟基和环氧基团的立体化学的前体。用Y（hfa）_3进行环化反应，得到8元和9元环醚扩链产物。如上所述，建立了7元、8元和9元环醚体系的拓展，用于多环醚的合成.多环醚类化合物的合成研究将上述方法应用于多环醚类化合物的合成。成功地合成了半短尾蛇毒素B的BCD-环（6，6，7-稠环体系）和雪卡毒素3C的DE-环（7，8-环体系）。少

1. Development of a catalytic and a recycle system of the medium-sized cyclic ethers constructionWe disclosed cyclization of hydroxy epoxides by use Eu(fod)_3 for the construction of medium-sized cyclic ethers. In order to develop into the efficient methodology from the point of view of an atomic economy, a catalytic and a recycle system of the methodology were examined. For these purposes, ionic liquid/organic solvent and fluorous solvent/organic solvent system were used. A catalytic amount of Lewis acid was expected to be concentrated under the conditions and accelerate the reaction. However, these attempts proved fruitless. Surveying of Lewis acid for the reaction revealed Y(hfa)_3 is an efficient Lewis acid, although it was not applicable to a catalytic use.2. Development of the methodology for the highly efficient and stereoselective construction of the polycyclic ether skeletonStereoselective construction of polycyclic ether skeleton was examined using the above mentioned methodo … More logy.1) Extension of the 7-membered cyclic ether : The phosphonate including an epoxy moiety was set as a chiral synthon. A sequence of Horner-Emmons type reaction using the reagent, anti-selective reduction of the carbonyl group induced by stereochemistry of the neighboring epoxy group provided a precursor with required stereochemistry of hydroxy and epoxy groups. Successive cyclization by use of Eu(fod)_3 gave the 7-membered cyclic ether-extended product.2) Extension of the 8- and 9-membered cyclic ethers : The chiral diepoxide derived from (+)-mannitol was set as a chiral synthon for these purposes. Addition of alkynic anion to the diepoxide applying the Yamaguchi's protocol afforded a precursor with required stereochemistry of hydroxy and epoxy groups. Successive cyclization by use of Y(hfa)_3 gave the 8- and 9-membered cyclic ether-extended product. As described above, extension of 7-, 8-, and 9-memberd cyclic ether systems for the synthesis of polycyclic ethers was established.3. Synthetic study of polycyclic ether compoundsThe above methodology was applied to synthesis of polycyclic ether compounds. The BCD-ring, the 6,6,7-fused ring system, of hemibrevetoxin B and the DE-ring, the 7,8-ring system, of ciguatoxin 3C were successfully synthesized. Less