Glucose diethyl dithioacetal, deamination

In attempting to obtain 2,5-anhydro-D-glucose diethyl dithioacetal, Defaye58 performed the nitrous acid deamination of 2-amino-2-deoxy-D-glucose diethyl dithioacetal (27) under weakly acidic conditions (acetic acid and sodium nitrite), and obtained a principal product later shown59 to be ethyl 2-S-ethyl-l,2-dithio-a-D-mannofuranoside (28). Shortly before, Horton and coworkers60 had reported the forma-... 

Solvent can have a marked effect on deamination in other respects. For example, it is commonly found that the extent of rearrangement is greater, the more polar the solvent 29,44 45 this effect is attributed to the increased lifetime of carbonium-ion species and their rearrangement to species that are more thermodynamically stable. Reactions performed at different pH values may also give different products, as illustrated by the deamination of 2-amino-2-deoxy-D-glucose diethyl dithioacetal hydrochloride in solution in (a) aqueous acetic acid and (b) hydrochloric acid (see p. 65). 

Deamination (see Section III,4) of 2-amino-2-deoxy-D-glucose diethyl dithioacetal at pH 0 and 5 respectively affords 31 (Refs. 128 and 133) and 30 (Ref. 134) a similar 1,2-episulfonium ion (35) was invoked131 as an intermediate in the formation of both products, attack occurring sequentially by the second sulfur atom and by solvent water in the former reaction, and by 0-4 of the sugar in the latter example. 

A new, three-step synthesis of 1-deoxy-D-fructose (27% overall yield) is based on reductive desulphurization of 2-amino-2-deoxy-D-glucose diethyl dithioacetal to give 2-amino-l,2-dideoxy-D-glucitol, which was oxidatively deaminated using... 

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