Studies on Glycosylation of<i>erythro</i>-β-Hydroxy-L-histidine. A Key Step of Bleomycin Total Synthesis
作者:Toshiaki Miyake、Tsutomu Tsuchiya、Sumio Umezawa、Seiichi Saito、Hamao Umezawa
DOI:10.1246/bcsj.59.1387
日期:1986.5
To improve the synthetic yield of bleomycin and its analogues, it is necessary to find the high yield procedure for condensation of sugar portion with the hydroxyl group of erythro-β-hydroxy-L-histidine moiety, preventing the N-glycosylation to imidazole. The present studies include the condensations of 4,6-di-O-acetyl-2,3-di-O-methyl-α-D-glucopyranosyl bromide (10) or 3,4,6-tri-O-acetyl-2-O-(2,4,
为了提高博来霉素及其类似物的合成收率,有必要找到糖部分与赤型-β-羟基-L-组氨酸部分的羟基缩合的高收率程序,防止N-糖基化为咪唑。目前的研究包括 4,6-di-O-acetyl-2,3-di-O-methyl-α-D-glupyranosyl bromide (10) 或 3,4,6-tri-O-acetyl-2 的缩合-O-(2,4,6-tri-O-acetyl-3-O-carbamoyl-α-D-mannopyranosyl)-α-L-gulopyranosyl bromide (3) 和 3,4,6-tri-O-acetyl -2-O-[2,4,6-tri-O-乙酰基-3-O-(N-乙酰氨基甲酰基)-α-D-吡喃甘露糖基]-α-L-吡喃甘露糖基溴(28)与多种受保护的衍生物赤型-β-羟基-L-组氨酸。结果表明,a) Nim-tosyl 基团最有效地防止 Nim-糖基化,