Synthesis of pyrazole C-nucleosides via Tin(IV) chloride-promoted reactions of β-d-ribofuranosyl cyanide with β-dicarbonyl compounds
作者:Monica Manferdini、Carlo F Morelli、Augusto C Veronese
DOI:10.1016/s0040-4020(01)01194-2
日期:2002.1
2,3,5-Tri-O-benzoyl-β-d-ribofuranosyl cyanide reacts with methyl acetoacetate and diethyl malonate in the presence of stoichiometric amounts of SnCl4 to give a β-d-ribofuranosyl-enaminoketoester and a β-d-ribofuranosyl-enaminodiester, respectively. The β-d-ribofuranosyl-enaminoketoester was debenzoylated, treated with 2,2-dimethoxypropane and tert-butyl-dimethylsilyl chloride to give the methyl 3-
在化学计量的SnCl 4存在下,2,3,5-三-O-苯甲酰基-β-d-呋喃呋喃糖基氰化物与乙酰乙酸甲酯和丙二酸二乙酯反应,得到β-d-呋喃核糖基-烯氨基酮酸酯和β-d-呋喃核糖基-烯氨基二酯。β型d-D-呋喃核糖基enaminoketoester被debenzoylated,用2,2-二甲氧基丙烷和处理过的叔丁基二甲基甲硅烷氯化物,得到3-氨基-3-(5'- ø -叔丁基二甲基-2',3' - Ø少量获得的α-异亚丙基-β-d-呋喃核糖基)-2-乙酰基丙酸酯及其少量的α-端基异构体。在控制的实验条件下进行β-端基异构体与肼,甲基-和苯肼的反应,以良好的收率得到作为β-端基异构体的吡唑C-核苷。