Conversion of 4(5)-methylthio-5(4)-nitroimidazole (11) into its silyl derivative and subsequent condensation with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (9) in the presence of trimethylsilyl trifluoromethanesulphonate for a short reaction time gave 4-methylthio-5-nitro-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)imidazole (15) with high regioselectivity; use of longer reaction times gave predominantly
将4(5)-甲
硫基-5(4)-硝基
咪唑(11)转化为其甲
硅烷基衍
生物,然后与1 - O-乙酰基-2,3,5-三-O-苯甲酰基-β - D-
呋喃呋喃糖缩合(9)在
三氟甲磺酸三甲基甲
硅烷基酯存在下短时间反应,得到具有高区域选择性的4-甲
硫基-5-硝基-1-(2,3,5-三-O-苯甲酰基-β - D-
呋喃呋喃糖基)
咪唑(15) ; 使用更长的反应时间主要得到了5-甲
硫基-4-硝基-异构体(14)。从(15)获得5-
氨基-4-甲基磺酰基-1-β- D-
呋喃呋喃糖基)
咪唑(7))分为三个步骤。