Synthesis of Substituted 3-Iodocoumarins and 3-Iodobutenolides via Electrophilic Iodocyclization of Ethoxyalkyne Diols
作者:Maddi Sridhar Reddy、Nuligonda Thirupathi、Madala Hari Babu、Surendra Puri
DOI:10.1021/jo400499r
日期:2013.6.21
A convenient and general synthesis of various 4-substituted 3-iodocoumarins and 4,5-disubstituted 3-iodobutenolides is described via an exclusive 6-endo-dig iodocyclization of 3-ethoxy-1-(2-alkoxyphenyl)-2-yn-1-ols and 5-endo-dig iodocyclization of 1-alkoxy-4-ethoxy-3-yn-1,2-diols, respectively. The reaction is carried out under very mild conditions using I2 in CH2Cl2 or toluene at room temperature