Synthesis of Medium-Sized Bicyclic Compounds by Intramolecular Cyclization of Cyclic<i>β</i>-Keto Radicals Generated from Cyclopropanols Using Manganese(III) Tris(pyridine-2-carboxylate) and Its Application to Total Synthesis of 10-Isothiocyanatoguaia-6-ene
作者:Nobuharu Iwasawa、Masahiro Funahashi、Satoshi Hayakawa、Taketo Ikeno、Koichi Narasaka
DOI:10.1246/bcsj.72.85
日期:1999.1
olefinic side chain are oxidized with manganese(III) tris(pyridine-2-carboxylate) to generate cyclic β-keto radicals with ring-expansion. These cyclize intramolecularly, affording bicyclic radical intermediates. The cyclized radicals are trapped with various radical-trapping reagents such as electron-rich or -deficient olefins, tributylstannane and diphenyl diselenide to give the corresponding functionalized
具有烯烃侧链的双环环丙醇被三(吡啶-2-羧酸)锰(III)氧化,生成环状 β-酮基并扩环。这些分子内环化,提供双环自由基中间体。环化的自由基被各种自由基捕获剂捕获,例如富电子或缺电子烯烃、三丁基锡烷和二苯基二硒化物,得到相应的官能化产物。双环产物的立体化学可以通过 MM2 力场计算得到很好的预测。使用该反应实现了异硫氰基倍半萜烯 10-isothiocyanatoguaia-6-ene 的立体选择性全合成。