TY - JOUR
T1 - C-nucleoside studies. Part 12. Synthesis of 3-α- and 3-β-(D-xylofuranosyl)pyrazoles
AU - Buchanan, J. Grant
AU - Moorhouse, Simon J.
AU - Wightman, Richard H.
PY - 1981
Y1 - 1981
N2 - 3-(2,3:4,5-Di-O-isopropylidene-D-gulo-pentahydroxypentyl)pyrazole (13) was prepared in four steps (45% overall yield) from D-gulonolactone (9). Treatment with 1-fluoro-2,4-dinitrobenzene and triethylamine followed by reaction with methanesulphonyl chloride in pyridine afforded 1-(2,4-dinitrophenyl)-3-(1-O- methylsulphonyl-2,3:4,5-di-O-isopropylidene-D-gulo-pentahydroxypentyl)pyrazole (15) which, on treatment with boron trichloride and subsequent methanolysis, followed by exposure to methanolic ammonia, yielded 3-(a-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-(ß-D-xylofuranosyl)pyrazole (7). The reactions of sodium benzoate in dimethylformamide with 1-methylsulphonyl-3-(1-O- methylsulphonyl-2,3:4,5-di-O-isopropylidene-D-gulo-pentahydroxypentyl)pyrazole (24) and with its D-ido-isomer (27) appear to involve a common fulvene-type intermediate (30).
AB - 3-(2,3:4,5-Di-O-isopropylidene-D-gulo-pentahydroxypentyl)pyrazole (13) was prepared in four steps (45% overall yield) from D-gulonolactone (9). Treatment with 1-fluoro-2,4-dinitrobenzene and triethylamine followed by reaction with methanesulphonyl chloride in pyridine afforded 1-(2,4-dinitrophenyl)-3-(1-O- methylsulphonyl-2,3:4,5-di-O-isopropylidene-D-gulo-pentahydroxypentyl)pyrazole (15) which, on treatment with boron trichloride and subsequent methanolysis, followed by exposure to methanolic ammonia, yielded 3-(a-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-(ß-D-xylofuranosyl)pyrazole (7). The reactions of sodium benzoate in dimethylformamide with 1-methylsulphonyl-3-(1-O- methylsulphonyl-2,3:4,5-di-O-isopropylidene-D-gulo-pentahydroxypentyl)pyrazole (24) and with its D-ido-isomer (27) appear to involve a common fulvene-type intermediate (30).
UR - http://www.scopus.com/inward/record.url?scp=51149211429&partnerID=8YFLogxK
U2 - 10.1039/P19810002258
DO - 10.1039/P19810002258
M3 - Article
SN - 1472-7781
SP - 2258
EP - 2266
JO - Journal of the Chemical Society, Perkin Transactions 1
JF - Journal of the Chemical Society, Perkin Transactions 1
ER -