New one-step process for the synthesis of functionalized 1,6-dioxaspiro[4,5]decanes
作者:Juan C. Carretero、Javier Rojo、Nuria Díaz、Chafiq Hamdouchi、Ana Poveda
DOI:10.1016/0040-4020(95)00453-f
日期:1995.7
β-Phenylsulfonyl dihydrofurans 1 were readily prepared by reduction of α-phenylsulfonyl-γ-lactones with DIBAL-H, followed by dehydration with MsCl-Et3N. Dihydrofurans 1 were deprotonated with n-BuLi and the resulting α-lithiated carbanion reacted with a wide variety of electrophiles. Particularly interesting is its reaction with γ-lactones because affords 1,6-dioxaspiro[4,5]decanes in good yields in
β-苯磺酰基二氢呋喃1被容易地通过还原α -苯磺酰基γ内酯用DIBAL-H的制备,接着用加入MsCl-ET脱水3 N.二氢呋喃1与n-BuLi去质子化了并且将得到的α-锂化负碳离子与反应各种各样的亲电试剂。特别令人感兴趣的是它与γ-内酯的反应,因为一步法即可获得高产率的1,6-二氧杂螺[4,5]癸烷。这种在非酸性条件下合成螺环酮的新方法是热力学控制的,并且在C-4,C-5和C-7处(但在C-2处)具有很高的立体选择性。