D-Glucose reaction

Acetamido-2-deoxy-D-glucose, reaction with acetyl chloride, 46,1... 

FIGURE 7-6 Formation of the two cyclic forms of D-glucose. Reaction between the aldehyde group at C-l and the hydroxyl group at C-5 forms a hemiacetal linkage, producing either of two stereoisomers, the a and fi anomers, which differ only in the stereochemistry around the hemiacetal carbon. The interconversion of a and fi anomers is called mutarotation. 

Figure 123 D-Glucose reaction under basic conditions.

Fig. 6. Glucose and cellobiose inhibition of enzymatic saccharification of cellulose. <25p cellulose (Solka Floe) in 10 ml tubes, agitated, O-O-O-O-control, A-A-A-A-control + 5mg/ml of cellobiose, - - -control +10 mg/ml of d-glucose. Reaction time —10 min. Temp. — 50° C, Cellulase —1.86 FP...

Starting with a mixture of a- and P-D-glucose, reaction in acetic anhydride with an acid catalyst, such as zinc chloride, at 24°C favors the formation of a-D-glucose pentaacetate (reaction 4.6). 

Reaction of diacetone allose with triflic anhydride gives the 3-0-trifyl derivative, which can be reduced with sodium borohydride, followed by the removal of the isopropylidene groups, to give 3-deoxy-D-glucose (reaction 4.98). 

In a similar manner, the 4-0-trifyl group of methyl 2,3,6-tri-0-benzoyl-4-0-trifyl a-D-galactopyranoside can be displaced by various nucleophiles such as azide or thioacetate to give 4-amino-4-deoxy D-glucose (reaction 4.110) or 4-deoxy-4-thio D-glucose (reaction 4.111). 

The methyl 2,3,6-tri-O-benzoyl-a-D-galactopyranoside can be fluorinated with DAST to give 4-deoxy-4-fluoro-D-glucose (reaction 4.112). 

This is then hydrolyzed by liver phosphatase to give D-glucose (reaction... 

The requisite key intermediates 4, 6a, and 8 were prepared as described in Figure 3 from easily accessible methyl 4,6-0-benzylidene-a-D-glucopyranoside 1 (59) only by two steps from D-glucose. Reaction of 1 with err-butyldimethylsilyl (TBS) chloride, already performed by the Fraser-Reid s group (40), produced an easily separable regioisomeric mixture of 2 a and 2b almost in a 1 1 ratio and an OH... 

---