C-nucleoside studies. Part 12. Synthesis of 3-α- and 3-β-(<scp>D</scp>-xylofuranosyl)pyrazoles
作者:J. Grant Buchanan、Simon J. Moorhouse、Richard H. Wightman
DOI:10.1039/p19810002258
日期:——
by exposure to methanolic ammonia, yielded 3-(α-D-xylofuranosyl)pyrazole (5). Oxidation of the pyrazole (13) and subsequent hydride reduction afforded, stereoselectively, 3-(2,3:4,5-di-O-isopropylidene-D-ido-pentahydroxypentyl)pyrazole(18); treatment of this in the same manner as the pyrazole (13) yielded 3-(β-D-xylofuranosyl)pyrazole (7).
由D-古洛糖内酯(9)分四个步骤(总收率45%)制备3-(2,3:4,5-二-O-异亚丙基-D-古洛基-五羟基戊基)吡唑(13 )。用1-氟-2,4-二硝基苯和三乙胺处理,然后与甲磺酰氯在吡啶中反应,得到1-(2,4-二硝基苯基)-3-(1 - O-甲基磺酰基-2,3:4,5-di - ö异亚丙基d -庚-pentahydroxypentyl)吡唑(15),其上用三氯化硼和随后的甲醇分解,然后暴露于氨的甲醇溶液,得到3-治疗(α- d-xylofuranosyl)吡唑(5)。吡唑(13)的氧化和随后的氢化物还原,立体选择性地得到3-(2,3:4,5-二-O-异亚丙基-D-氨基-五羟基戊基)吡唑(18);以与吡唑(13)相同的方式对其进行处理,得到3-(β- D-木呋喃糖基)吡唑(7)。