CC bond formation by radical cyclization: Facile syntheses of [6,6]pyranothiopyrans and [6,6]pyridothiopyrans
作者:K. C. Majumdar、S. Sarkar、P. Pal、S. Muhuri
DOI:10.1002/jhet.220
日期:2009.11
4‐Chloromethylthiopyrano[3,2‐c][1]benzopyran‐5‐(2H)‐ones were refluxed with o‐bromophenols in acetone in the presence of anhydrous potassium carbonate and sodium iodide to afford a number of 4‐aryloxymethylthiopyrano[3,2‐c][1]benzopyan‐5‐(2H)‐ones in 72–79% yields. These compounds were refluxed with tri‐n‐butyltin hydride and azobisisobutyronitrile in dry benzene for 7–8 h to give [6,6]pyranothiopyrans
在无水碳酸钾和碘化钠存在下,将4-氯甲基硫代吡喃并[3,2- c ] [1]苯并吡喃-5-(2 H)-与邻溴酚在丙酮中回流,制得许多4-芳氧基甲硫吡喃[ 3,2- [ c ] [1]苯并吡喃-5-(2 H)-1 ,产率72-79%。这些化合物与三回流Ñ在无水苯-butyltin氢化物和偶氮二异丁腈为7-8小时,得到[6,6]中具有良好的非对映选择性76-84%的收率pyranothiopyrans。同样,[6,6]吡啶硫吡喃类化合物也以非对映选择性优异的70-75%的产率合成。J.杂环化学,(2009)。