Reactions That Proceed with Retention of the Nitro Group

Reactions That Proceed with Retention of the Nitro Group 

In order to minimize such possible side-reactions as anomerization of glycosides and acetolysis of acetal structures, alternative techniques of acetylation have been studied. Whereas basic catalysis leads to severe complications in certain nitro sugar derivatives (see Section IV,2a and c pp. 124, 129), boron trifluoride etherate has proved to be an excellent agent for satisfactory acetylation of glycosides, O-benzyl-idenated glycosides, and disaccharides that contain a deoxynitro function.148,149 

Of the three deoxynitroinositols 100-102, only one, namely, the muco-3 isomer (101) forms a diisopropylidene acetal (151), whereas the others do not react with acetone under ordinary conditions.102 197 The boat form depicted for 151 appears reasonable, and is supported 

Free 3-deoxy-3-nitro-D-glucose was obtained151 by hydrolysis of its methyl /3-D-pyranoside (40) with 5 M hydrochloric acid for 90 min at 100°. These conditions appear to be somewhat more strenuous than those required for hydrolysis of ordinary hexopyranosides. On the other hand, debenzylidenation of 2-O-acetyl,04 2-deoxy,64 85,80 152 2-acetamido-2-deoxy,155 and 2-O-alkyl149,156 derivatives of methyl 4,6-0- 

HOCH HOCH ch,no2 HCOH 1 HOCH, H CHjNOj HOCH 0 S CH,NQI 

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