6-Exo free radical cyclization of acyclic carbohydrate intermediates: a new synthetic route to enantiomerically pure polyhydroxylated cyclohexane derivatives
摘要:
The 6-exo free radical cyclization of conveniently functionalized acyclic carbohydrate derivatives is a new and efficient method for the asymmetric synthesis of polyhydroxylated cyclohexane compounds (aminocyclitols, pseudosugars). The scope and versatility of this synthetic route has been analyzed by changing the absolute configuration of the radical precursors and the nature of the radical trap. The yield and stereoselectivity in this process is very structure dependent.
描述了通过与3,5-二叔丁基-1,2-苯并醌反应而将选择性保护的庆大霉素和西索霉素衍生物转化为1-和3-氧代化合物。通过应用适当的还原技术,这些氧代-氨基糖苷已被转化为新颖的1-和3- epi-,1-和3-脱氨基-1-和-3-羟基-,1-和3-脱氨基-1-和-。 3-表羟基和1-脱氨基衍生物。所述的研究13的1- C NMR参数外延-和1-脱氨基衍生物已导致新颖的解决方案的构象为这些新的氨基糖苷类的分配。