Glucose in methanol

The reduction of a dinitro ketone to an azo ketone is best achieved with glucose. 2,2 -Dinitrobenzophenone treated with glucose in methanolic sodium hydroxide at 60° afforded 82% of dibenzo[c,f [i 2]diazepin-l 1-one whereas lithium aluminum hydride yielded 24% of bis(o-nitrophenyl)methanol [575], Conversion of aromatic nitro ketones with a nitro group in the ring into amino ketones has been achieved by means of stannous chloride, which reduced 4-chloro-3-nitroacetophenone to 3-amino-4-chloroacetophenone in 91% yield [178]. A more dependable reagent for this purpose proved to be iron which, in acidic medium, reduced m-nitroacetophenone to m-aminoacetophenone in 80% yield and o-nitrobenzophenone to o-aminobenzophenone in 89% yield (stannous chloride was unsuccessful in the latter case) [903]. Iron has also been used for the reduction of o-nitrochalcone, 3-(o-nitrophenyl)-l-phenyl-2-propen-l-one, to 3-(o-aminophenyl)-l-phenyl-2-propen-l-one in 80% yield [555]. 

Table V contains a list of the absolute rates and relative rates of migration for various carbohydrates in methanolic solutions of potassium acetate and sodium acetate. Table IV shows the effect of different salts on the absolute rates and relative rates of D-xylose and D-glucose in methanol. The ability...

Photolysis of D-glucose in methanol containing titanium(IV) chloride gave the D-xy/o-pentodialdose glycoside acetal 184 in 60% yield D-galactose behaved similarly.386... 

Various thiazole anion-radicals have been characterized by ESR. Tordo and co-workers have generated several nitrothiazole anion radicals (e.g., 204 and 205) by reduction of the precursors with glucose in methanol containing... 

ARP from glycine, valine, diglycine, triglycine was synthesized by the method described by Sherr et al (1980) by the reaction of amino acid or peptide with glucose in methanol. Then, the ARP was purified using Dowex 50W-X4 column chromatography. The chemical structures were confirmed by MS and NMR. 

The reaction of 1,2-anhydro sugars with alcohols promises to be a useful method for the preparation of glycosides. Brigl (S3) prepared methyl iS-D-glucopyranoside 3,4,6-triacetate by evaporating a solution of 1,2-anhydro-3,4,6-tri-0-acetyl-D-glucose in methanol to dryness. Recently, Lemieux and Huber (54) have extended the method to the synthesis of sucrose (see Chapter IX). 

Reaction of D-glucose in methanol proceeds through the a- and P-furanoside forms, through the P-pyranoside form, ultimately to the a-pyranoside form, which becomes the predominant product. 

Since an enzyme is a biological catalyst and therefore merely accelerates a reaction, it cannot alter the position of equilibrium in a reversible reaction. The hydrolysis of p-methylglucoside is reversible and emulsin should therefore be capable also of synthesising this compound frc n glucose and methanol. This synthesis can actually be carried out by the action of the enzyme on glucose dissolved in an excess of methanol, the excess of the alcohol throwing the equilibrium over to the left. Owing to experimental difficulties, this reaction is not here described. 

Acetamiprid and its metabolites. A GC method has been developed for the determination of acetamiprid and its metabolites IM-2-1, IM-0, IC-0 (Figure 4) and IM-O-glucose in crops. As shown in Figure 5, acetamiprid and its metabolites in crops are extracted with methanol and derivatized to methyl 6-chloronicotinate (IC-O-Me) through alkaline hydrolysis, potassium permanganate oxidation and then esterification... 

For the hydrosilylation reaction various rhodium, platinum, and cobalt catalysts were employed. For the further chain extension the OH-functionalities were deprotected by KCN in methanol. The final step involved the enzymatic polymerization from the maltoheptaose-modified polystyrene using a-D-glucose-l-phosphalc dipotassium salt dihydrate in a citrate buffer (pH = 6.2) and potato phosphorylase (Scheme 59). The characterization of the block copolymers was problematic in the case of high amylose contents, due to the insolubility of the copolymers in THF. 

Reaction of glucose with methanol and gaseous HCl yields four acetal products, the a- and P-pyran-osides and a- and P-furanosides, which may be separated. The pyranosides are the predominant components, and the major product is the a-pyran-oside. This is perhaps unexpected, in that the P-pyranoside has ah its substituents equatorial. 

Levoglucosan 14, which is derived from Z)-glucose, has a strained ether ring system. Oxidation in methanol causes carbon-carbon bond cleavage to yield D-arabinose. High yields are obtained in methanol with addition of sodium methoxide... 

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