β-Elimination of 2-O-(4-O-methyl-α-d-glucopyranosyluronic acid)-d-xylose with methylsulphinyl carbanion and hydrolysis of the hex-4-enopyranosiduronic linkage
作者:Kazumasa Shimizu
DOI:10.1016/s0008-6215(00)80394-8
日期:1981.6
treatment with m sodium methylsulphinylmethanide at 25°, 2- O -(4- O -methyl-α- d -glucopyranosyluronic acid)- d -xylose ( 1 ) was rapidly degraded by β-elimination, to form 2- O -(4-deoxy-β- l - threo -hex-4-enopyranosyluronic acid)- d -xylose ( 2 ). The kinetics of hydrolysis of 1 and 2 in 0.5 m sulphuric acid have been studied. Compound 2 was hydrolysed 70 times faster than 1 . Compared with the rate coefficients
摘要在甲基磺化亚甲基间甲烷磺酸钠在25°处理时,β-消除作用可快速降解2-O-(4-O-甲基-α-d-吡喃葡萄糖基糖醛酸)-d-木糖(1),形成2-O-。 (4-脱氧-β-1-苏式-hex-4-enopyranosyluronic酸)-d-木糖(2)。研究了在0.5 m硫酸中1和2的水解动力学。化合物2的水解速度比1快70倍。与其他相关化合物的速率系数相比,2的水解速率与2- O-(4- O-甲基-α-d-吡喃葡萄糖基)-d-木糖的水解速率大致相同,是木糖的3.5倍,两倍与O-(4-O-甲基-α-d-吡喃葡萄糖基糖醛酸)-(1→2)-O-β-d-吡喃吡喃糖基-(1→4)-d-木糖中的木糖苷键一样快。