Of D-lactose

The corresponding tri- and hexa-fluoroacetylacetonates may be similarly prepared. The stability of the acetylacetonate is such that not only can it be resolved on passage through a column of D-lactose, but the enantiomers retain their integrity on nitration or bromination. 

Kuusisto, J., Tokarev, A.V., Murzina, E.V., Roslund, M.U., Mikkola, J.-P., Murzin, D., and Salmi, T. (2007) From renewable raw materials to high-value added fine chemicals - catalytic hydrogenation and oxidation of D-lactose. Catal. Today, 121, 92-99. 

Fig. 2.54 presents a two-dimensional carbon-proton shift correlation of D-lactose after mutarotational equilibration (40% a-, 60% / -D-lactose in deuterium oxide), demonstrating the good resolution of overlapping proton resonances between 3.6 and 4 ppm by means of the larger frequency dispersion of carbon-13 shifts in the second dimension. The assignment known for one nucleus - carbon-13 in this case - can be used to analyze the crowded resonances of the other nucleus. This is the significance of the two-dimensional CH shift correlation, in addition to the identification of CH bonds. For practical evaluation, the contour plot shown in Fig. 2.54(b) proves to be more useful than the stacked representation (Fig. 2.54(a)). In the case of D-lactose, selective proton decoupling between 3.6 and 4 ppm would not afford results of similiar quality. 

Partial Resolution of Optical Isomers. Co(admh)(acac)2 was resolved partially on a previously described 230 x 3.9 cm o.d. column of D-(+)-lactose (10). In two separate chromatograms, 130 mg of sample dissolved in 1.5 ml of benzene was placed on the column and eluted with l.-l benzene-hexane. The entire eluted solution was collected in two parts. The first fractions from each chromatogram were combined and evaporated to dryness. The enantiomer in excess was then concentrated by extracting the residue with 1 ml of hexane. 

Alternatively, one of the metal-oxygen bonds in the acetylacetonate can cleave before or after electrophilic attack on the chelate ring that is undergoing cleavage, forming a five-coordinate intermediate. With the subsequent loss of a proton, a chelate ring with a 3-halo substituent is obtained. The trisacetylacetonates of Cr(III), Co(III), and Rh(III) were partially resolved on a 16-foot column of D-lactose hydrate. The optical activity of each of these chelates was measured before and after being subjected to a number of electrophilic substitution reactions. It was found that the substitution reactions did not cause total racemization, and therefore it was concluded that this alternative mechanism is unlikely (49). 

D (+) Galactose is a constituent of numerous polysaccharides It is best obtained by acid hydrolysis of lactose (milk sugar) a disaccharide of d glucose and d galactose L (—) Galactose also occurs naturally and can be prepared by hydrolysis of flaxseed gum and agar The principal source of d (+) mannose is hydrolysis of the polysaccharide of the ivory nut a large nut like seed obtained from a South American palm... 

La.ctose, Lactose [63-42-3] (milk sugar), 20, makes up about 5% of cow s milk. Lactose is a disaccharide composed of D-glucose... 

Figure 8.7 Reaction schemes for hydrogenation of d-fructose, d-xylose, and d-lactose.

J.-P., Kuusisto, J., Kustov, L.M., and Murzin, D. (2007) Application of in-situ catalyst potential measurements for estimation of reaction performance D-lactose oxidation over Au and Pd catalysts. Chem. Eng.J., 134, 153-161. 

The concentration versus lactose conversion (X) plots have maxima for B and C, while the concentrations of D, E, F and G increase monotonously with conversion E, F and G showing a steep decrease at high lactose conversions. 

Lactosone was first prepared by the hydrochloric acid decomposition of the phenylosazone,1 although it had been noted that, in acid solutions, lactose phenylosazone forms an anhydride.197 Since its discovery,17 the benzaldehyde method has usually been employed,6-10-28 because it avoids the risks of osone hydrolysis and of alteration to the osazone. Lactosone is hydrolyzed by hot, dilute, mineral acid to D-glucosone and D-galactose.1-6 It reacts with cyanide to form an analog of iminoascorbic acid which, on acid treatment, is converted into a mixture of D-glucoascorbic acid and D-galactose.10... 

A similar study has been conducted in which the interaction of d-amphetamine sulfate with spray-dried lactose was investigated [32], Upon storage at elevated temperatures, discoloration of the powder blends was noted, and the new absorption bands characterized. One maximum was noted at 340 nm, and this was attributed to the chemisorption of the amine onto the lactose particles. The other band appeared at 295 nm and was attributed to the new compound ([Pg.47]

---