Aldose-aminoguanidine condensation products: syntheses and n.m.r. studies
作者:Lászlo Szilágyi、Zoltán Györgydeák、Helmut Duddeck
DOI:10.1016/0008-6215(86)84006-x
日期:1986.12
Abstract The condensation products of aldoses with aminoguanidine exist in aqueous solution at pH 6 as cyclic pyranosylaminoguanidines with the protonated aminoguanidine substituent at C-1 equatorial, and at pH 12 and in methyl sulfoxide as acyclic E -carboximidamidehydrazones. The cyclic isomers are present exclusively when mineral acid salts of the condensation products are dissolved in methyl sulfoxide
摘要醛糖与氨基胍的缩合产物在pH 6的水溶液中以环状吡喃糖基氨基胍存在,在C-1赤道处为质子化的氨基胍取代基,在pH 12时以甲基亚砜的形式存在于无环的E-羧酰亚胺酰胺hydr中。当缩合产物的无机酸盐溶于甲基亚砜时,仅存在环状异构体。已通过1 H-,13 C-和15 Nn.mr方法研究了氨基胍部分的质子化和互变异构位点,并讨论了pH依赖性环-非环互变的机理。