Nitrogen-containing carbohydrate derivatives. XIV. Configurational studies on amino-sugars using cuprammonium solutions.
A study has been made of the optical rotational shifts and conductance changes in cuprammonium solutions of eight isomeric amino-glycosides. The results are in agreement with the findings of Reeves for vicinal diol systems. Care must be taken in using small optical rotational shifts alone as evidence for the absence of complexing with a vic-amino-alcohol grouping. These techniques have been used to relate methyl 5-amino-1,3-O-benzylidene-5-deoxy-β-D-fructoside and -α-L-sorboside to their respective hydroxy-compounds.
A study of the structure of bluensomycin with the tetramminecopper reagent.
A polarimetric study was made of the interaction of the tetramminecopper (TACu) reagent and the Cupra B reagent with bluensomycin, desamidinodecarbamoyl (DADC) bluensomycin, and several reference compounds of the streptomycin series. The results obtained with TACusupport the choice of 5b as the correct formula for DADC-bluensomycin. It follows that bluensomycin is 9, and bluensidine is lD~l-O-carbamoyl-3-deoxy-3-guanidinosc3/ZZo-inositol (2). A phosphorylated aminosugar, D-glucosamine 1-phosphate, gives a normal J[M] value with TACu.
Nitrogen-containing carbohydrate derivatives : Part IV. Studies on the optical rotatory dispersion and circular dichroism of carbohydrate C-nitro alcohols. III☆
Abstract The optical rotatory dispersion and circular dichroism of carbohydrate C -nitro alcohols were measured. Evidence is presented that the signs of the Cotton effect about 310 mμ and of the ellipticity of the 310 mμ band are closely related to the absolute configuration at C-2 of carbohydrate C -nitro alcohols. Carbohydrate C -nitro alcohols in which the asymmetric carbon atom adjacent to the nitro methyl group belongs to the s -series exhibit positive Cotton effects and positive c.d. maxima (or shoulders), whereas C -nitro alcohols in which the adjacent carbon atom is of the r -series show negative Cotton effects and negative c.d. maxima (or shoulders). These deductions permit the ready determination of the absolute configuration of epimeric nitro alcohols obtained by the nitromethane synthesis for elongation of carbohydrate chains.