Regiochemical study of nBu3SnH–AIBN-mediated aryl-radical cyclization of different 3-(2-bromophenyl sul fenylmethyl)coumarins, 3-(2-bromophenylsulfonyl-methyl)coumarins, and 6-[(2-bromophenoxy)methyl]-4-methoxypyran-2-ones have been investigated with the formation of different [6,6]-fused and spirocylic heterocycles. The sulfides and ethers were prepared from 3-chloromethyl coumarin and 6-(bromomethyl)-4-methoxy pyran-2-one with different 2-bromothiophenol and 2-bromophenols under classical alkylation condition. The corresponding sulfones were prepared by oxidation of the sulfides with m-CPBA.Key words: aryl-radical cyclization, coumarin and pyrone derivatives, 5-exo-trig, 5-endo-trig, nBu3SnH, sulfur heterocycles.
对 nBu3SnH-AIBN 介导的不同 3-(2-溴苯基磺酰甲基)香豆素、3-(2-溴苯基磺酰甲基)香豆素和 6-[(2-溴苯氧基)甲基]-4-甲氧基吡喃-2-酮的芳基自由基环化进行了区域化学研究,并形成了不同的 [6,6]- 融合和螺环杂环。在经典的烷基化条件下,由 3-氯甲基香豆素和 6-(溴甲基)-4-甲氧基吡喃-2-酮与不同的 2-溴噻吩酚和 2-溴苯酚制备硫化物和醚。关键词:芳基自由基环化、香豆素和吡喃酮衍生物、5-外-三叉、5-内-三叉、nBu3SnH、硫杂环。