Sanz Roberto, Miguel Delia, Martínez Alberto, Pérez Antonio
Departamento de Química, Area de Química Organica, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001-Burgos, Spain.
J Org Chem. 2006 May 12;71(10):4024-7. doi: 10.1021/jo060271d.
Treatment of benzyl 2-halophenyl ethers with 3 equiv of t-BuLi results in Li-halogen exchange and lithiation at benzylic methylene simultaneously. These dianions do not undergo Wittig rearrangement and can be trapped with electrophiles. Their reactions with carboxylic esters afford the corresponding 2-aryl-3-hydroxy-2,3-dihydrobenzo[b]furans as a mixture of diastereoisomers. Subsequent acid-catalyzed or mediated dehydration gives moderate to good overall yield of a variety of 2-aryl-3-substituted benzo[b]furans.
用3当量的叔丁基锂处理苄基2-卤代苯基醚会同时发生锂-卤素交换和苄基亚甲基的锂化反应。这些双阴离子不会发生维蒂希重排，并且可以被亲电试剂捕获。它们与羧酸酯的反应会生成相应的2-芳基-3-羟基-2,3-二氢苯并[b]呋喃，为非对映异构体的混合物。随后的酸催化或介导的脱水反应能以中等至良好的总收率得到多种2-芳基-3-取代的苯并[b]呋喃。
