Reactions That Alter or Remove the Nitro Group

Reactions That Alter or Remove the Nitro Group 1. Catalytic Hydrogenation 

Sugar derivatives containing an a-nitroalkene grouping can usually be saturated, without affecting the nitro group, by brief hydro- 

The Nef reaction12,13 is the conversion, by treatment with mineral acid, of a nitronate into an aldehyde or ketone. Early applications of this reaction to deoxynitroalditols have proved extremely useful in sugar synthesis, and have been reviewed.3 The general utility of the reaction is emphasized by several more-recent syntheses of aldoses,16-183,22,23 2-deoxyaldoses,18a,133 135 ketoses,29-34 and disacchar- 

An interesting study has been made of the photolysis of a nitro-olefinic sugar.148b Irradiation, at 253.7 nm, of an acetone solution of cis-6,7,8-trideoxy-l,2 3,4-di-0-isopropylidene-7-nitro-o-D-gflIocfo-oct-6-enose (135) gave a complex mixture from which there were isolated the trans isomer 136 and the cis and trans isomers of 6,8-dideoxy-l,2 3,4-di-0-isopropylidene-a-D-gaZacto-oct-5-enos-7-ulose (137 and 138). Insofar as the formation of the two ketones involves the loss of 

In the course of the elucidation of the structure of evemitrose (see Section 1,2, p. 70), /3-elimination of nitrous acid was effected148 by treatment of the corresponding hexonolactone with methanolic potassium acetate. Another reaction involving loss of this acid will be described in Section IV,2c (see p. 129). 

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