α,β-Unsaturated and cyclopropyl acyl radicals, and their ketene alkyl radical equivalents. Ring synthesis and tandem cyclisation reactions
作者:Christopher J. Hayes、Nicola M. A. Herbert、Nicole M. Harrington-Frost、Gerald Pattenden
DOI:10.1039/b413815p
日期:——
25a on treatment with Bu(3)SnH-AIBN. Furthermore, in the presence of methanol the only product from this reaction was the bis(methyl ester) dimer 25b, thereby lending further credence to the involvement of ketene alkyl radical intermediates in these reactions, and in the aforementioned reactions involving 2,6- and 2,7-diene selenyl esters. Treatment of the cyclopropane selenyl esters and , containing
用Bu(3)SnH-AIBN处理α,β-不饱和硒基酯12和14分别通过推测的α-烯酮烷基自由基中间体产生相应的2-环己酮13和15。10.相反,2,7-二烯酯34和39经历串联自由基环化,产生二喹烷,例如(76%),并且相应的丙二烯取代的α,β-不饱和硒烯基酯48在用Bu处理时得到环辛二烯酮56。 (3)SnH-AIBN在回流的苯中。衍生自菊花酸的硒基酯19经Bu(3)SnH-AIBN处理后,会生成γ-δ-不饱和醛22和相应的二聚体25a的混合物。此外,在甲醇存在下,该反应的唯一产物是双(甲酯)二聚物25b,因此进一步证明了烯酮烷基自由基中间体在这些反应中以及在涉及2,6-和2,7-二烯硒烯基酯的上述反应中的参与。用Bu(3)SnH-AIBN处理环丙烷硒烯基酯和在其侧链中含有酮和氧基官能团的化合物,可以很好地合成烯醇内酯66(76%)和反式稠合双环[ 6.1.0]壬烷67(80-95%)。