Synthesis of 5?-amino- and 5?-azido-2?,5?-dideoxy nucleosides from thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione
作者:A. A. El-Barbary、N. R. El-Brollosy、E. B. Pedersen、C. Nielsen
DOI:10.1007/bf00807434
日期:1995.5
Thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (4) was silylated and condensed with methyl 5-azido-2,5-dideoxy-3-O-(4-methylbenzoyl)-D-erythro-pentofuranoside (2) in the presence of TMS triflate to afford the corresponding protected nucleoside 6 and acyclic nucleoside 7. Deprotection of 6 with MeONa/MeOH at room temperature gave 1-(5-azido-2,5-dideoxy-alpha-D-erythro-pentofuranosyl)-thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (8) and the corresponding beta anomer 9, whereas compound 7 yielded 5-azido-2,5-dideoxy-1-(2,4-dioxo-1,2,3,4-tetrahydrothieno [2,3-d]pyrimidin-1-yl)-1-O-methyl-D-erythro-pentitol (10) under the same reaction conditions. 1-(5-Amino-2,5-dideoxy-beta-D-erythro-pentofuranosyl)thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (11) was obtained on treating 9 with Ph(3)P in pyridine followed by hyrolysis with NH4OH. The anomeric nucleosides 14 and 15 and the corresponding acyclic nucleoside 16 were obtained when 4 was trimethylsilylated and condensed with methyl 2-deoxy-3,5-di-O-(4-methylbenzoyl)-D-erythro-pentofuranoside (3) followed by deprotection with MeONa in MeOH. Compounds 8 and 9 were also obtained when the anomeric mixture 14/15 was treated with a mixture of NaN3, Ph(3)P, and CBr4 in dry DMF at room temperature.