An efficient synthesis of cycloalkane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using (1-aryl-2-bromoethyl)-dimethylsulfonium bromides: application to a one-pot synthesis of tetrahydroindol-4(5H)-one

作者：Nambu Hisanori^*; Fukumoto Masahiro; Hirota Wataru; Ono Naoki; Yakura Takayuki

来源：Tetrahedron Letters, 2015, 56(29): 4312-4315.

DOI：10.1016/j.tetlet.2015.05.069

• Cyclopropane
• 1,3-Cyclohexanediones
• Sulfonium salts
• Indole
• One-pot synthesis

An efficient synthesis of cyclohexane- and cyclopentane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using sulfonium salts was achieved. The reaction of 1,3-cycloalkanediones with (1-aryl-2-bromoethyl)-dimethylsulfonium bromides and powdered K2CO3 in EtOAc provided the corresponding spirocyclopropanes in high yields. Furthermore, a one-pot synthesis of tetrahydroindol-4(5H)-one from 1,3-cyclohexanedione was achieved using the present protocol and a sequential ring-opening cyclization of spirocyclopropane with a primary amine.

• 出版日期2015-7-15