Tandem β-Fragmentation−Hydrogen Abstraction Reaction of Alkoxy Radicals in Steroidal Systems
作者:Alicia Boto、Raimundo Freire、Rosendo Hernández、Ernesto Suárez、María S. Rodríguez
DOI:10.1021/jo962252h
日期:1997.5.1
have been prepared in order to test a new tandem beta-fragmentation-hydrogen abstraction reaction. The alkoxy radicals generated by irradiation of these alcohols with visible light in the presence of (diacetoxyiodo)benzene, iodine, and molecular oxygen undergo a beta-fragmentation reaction followed by peroxidation of the C-radical formed. The peroxy radical reacts further with iodine to give an alkoxy
多种叔或半缩醛甾醇,2-羟基-3,4-二or-2,3-仲胆甾醇-5-酮2,5-半缩醛(1),2beta,3beta-dihydro-3'H-cyclopropa [2 ,3]-胆甾烷5alpha-ol(7),3beta-苯基-5alpha-羟基胆甾烷-2-1(10),5alpha-羟基胆甾烷-3-1(15),3beta,5alpha-二羟基胆甾聚糖-7-one 3-为了测试新的串联β-片段化-氢提取反应,已经制备了乙酸酯(21)和4,4-二甲基-19-羟基-5α-胆甾醇-3-一19,3-半缩醛(27)。在(二乙酰氧基碘)苯,碘和分子氧的存在下,用可见光照射这些醇而生成的烷氧基进行β-片段化反应,然后对所形成的C-自由基进行过氧化。过氧自由基进一步与碘反应,生成烷氧基和碘氧基(IO(*))。