Synthesis of 7-hydroxy-6H-benzo[c]chromen-6-ones based on a ‘[3+3] cyclization/domino retro-Michael–aldol–lactonization’ strategy
作者:Ehsan Ullah、Bettina Appel、Christine Fischer、Peter Langer
DOI:10.1016/j.tet.2006.07.084
日期:2006.10
The TiCl4-mediated [3+3] cyclization of 2,4-bis(trimethylsilyloxy)penta-1,3-diene with 3-silyloxyalk-2-en-1-ones afforded 2-acetylphenols, which were transformed into functionalized chromones. The Me3SiOTf-mediated condensation of the latter with 1,3-bis(silyl enol ethers) and subsequent domino ‘retro-Michael–aldol–lactonization’ reaction afforded 7-hydroxy-6H-benzo[c]chromen-6-ones.
TiCl 4介导的2,3-双(三甲基甲硅烷氧基)戊-1,3-二烯与3-甲硅烷氧基烷-2-烯-1-酮的[3 + 3]环化反应提供了2-乙酰基酚,将其转化为官能化的色酮。Me 3 SiOTf介导的后者与1,3-双(甲硅烷基烯醇醚)的缩合反应以及随后的多米诺骨牌“迈克尔-复古-醛醇-内酯化”反应提供了7-羟基-6 H-苯并[ c ] chromen-6-那些。