2- Nitro-l,3-diols, cyclic

Cyclic 2>nitro l,3>diols from dialdehydes Aliphatic nitro compounds from aci-nitro compounds by dry acidification... 

Malinowski and T. Urbanski (60J advanced a suggestion that a hydrogen bond can exist between the nitro and the hydroxy group in nitro alcohols. This was based on the experimental fact that 2-nitropropane-l,3-diol (I) formed cyclic acetals-1,3-dioxane derivatives (II) and ketals with great difficulty, while on the contrary the triol 2-hydroxymethyI-2-nitro-propane-l,3-diol (11 ) forms the corresponding cyclic acetal (IV) and ketal with great ease. 

Oxirans. - Treatment of methyl 4,6-0-benzylidene-a-D-glucopyranoside with a mixture of diethyl carbonate and potassium carbonate in DMF has afforded directly a new simple synthesis of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-allopyranoside. The corresponding 2,3-cyclic carbonate is postulated as an intomediate. Some carbohydrate examples have been published of the use of sodium hydride and p-toluenesulfonyl chloride for the conversion of 1,2-diols to epoxides. Simple routes to the Cemy epoxides 6 and 7 finom D-glucal have been develc red (Scheme 1). In this scheme the flrst step involves a dehydration elimination with allylic rearrangement Syntheses of methyl 2,3-anhydro-a- and L-OTthiofuranoside have been reported. Some nitro-sugar epoxides are mentioned in Chapter 10. 

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