Synthesis of 1-(3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranosyl)uracils via an ?,?-unsaturated aldehydrohexose
摘要:
Mercuric catalyzed hydrolysis of acetylated L-rhamnal 1 gave the alpha,beta-unsaturated aldehyde 2. 1,2,4-Triazole was coupled, in a Michael type addition reaction, to 2 at C-3 in the presence of 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) to give, after acetylation at the anomeric center, an anomeric mixture of 1,5-di-O-acetyl-3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranose (3). Reaction of 3 with silylated 2,4-dihydroxypyrimidines 4 in the presence of trimethylsilyl triflate as catalyst followed by deprotection with 33% methylamine in absolute ethanol afforded the corresponding nucleosides 7 and 8.
Synthesis of 1-(3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranosyl)uracils via an ?,?-unsaturated aldehydrohexose
作者:Krzysztof Walczak、Jesper Wengel、Erik B. Pedersen
DOI:10.1007/bf00810947
日期:1992.4
Mercuric catalyzed hydrolysis of acetylated L-rhamnal 1 gave the alpha,beta-unsaturated aldehyde 2. 1,2,4-Triazole was coupled, in a Michael type addition reaction, to 2 at C-3 in the presence of 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) to give, after acetylation at the anomeric center, an anomeric mixture of 1,5-di-O-acetyl-3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranose (3). Reaction of 3 with silylated 2,4-dihydroxypyrimidines 4 in the presence of trimethylsilyl triflate as catalyst followed by deprotection with 33% methylamine in absolute ethanol afforded the corresponding nucleosides 7 and 8.