Synthesis and conformational properties of sugar amides and thioamides
摘要:
The synthesis of deoxythioformamido and deoxythioacetamido derivatives of 1,2:3,4-di-O-isopropylidene-alpha-D-galactopyranose, 1,2:3,5-di-O-isopropylidene-alpha-D-glucofuranose and 2,3:4,5-di-O-isopropylidene-beta-D-fructopyranose at the primary carbon atom has been effected by thionation of the corresponding sugar amides. Formamides and thioformamides existed as a mixture of the Z (major) and E (minor) stereomers around the N-C(=X) bond in CDCl3 solutions, while the Z rotamer was the sole one detected in the cases of acetamides and thioacetamides.
Conformational energetics of sugar thioureas and synthesis of glycosyl thioureido sugars
作者:JoséM. García Fernández、Carmen Ortiz Mellet、Víctor M. Díaz Pérez、JoséL. Jiménez Blanco、José Fuentes
DOI:10.1016/0040-4020(96)00673-4
日期:1996.9
of the reaction of 6-deoxy-6-isothiocyanatoaldopyranoside derivatives with ammonia depend strongly on the nature of the hydroxyl protecting groups and solvent. In pyridine as solvent, the expected thioureas are obtained as the sole reaction products. A marked preference for the E configuration at the sugarNHC(S) bond is observed for silylated as compared to acetylated derivatives. Rotational barrier
Synthesis and conformational properties of sugar amides and thioamides
作者:Carmen Ortiz Mellet、Alberto Moreno Marín、José M. García Fernández、José Fuentes
DOI:10.1016/s0957-4166(00)80381-x
日期:1994.12
The synthesis of deoxythioformamido and deoxythioacetamido derivatives of 1,2:3,4-di-O-isopropylidene-alpha-D-galactopyranose, 1,2:3,5-di-O-isopropylidene-alpha-D-glucofuranose and 2,3:4,5-di-O-isopropylidene-beta-D-fructopyranose at the primary carbon atom has been effected by thionation of the corresponding sugar amides. Formamides and thioformamides existed as a mixture of the Z (major) and E (minor) stereomers around the N-C(=X) bond in CDCl3 solutions, while the Z rotamer was the sole one detected in the cases of acetamides and thioacetamides.