Glucose diethyl dithioacetal

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). 

A solution of the dry D-glucose diethyl dithioacetal (10.725 g 37.5 mmol) 2-methoxypropene (3.245 g 45 mmol) in anhydrous DMF (130 mL) and p-toluenesulfomc acid (375 mg) was kept for 68 h at 0°C. The homogeneous mixture was kept with exclusion moisture until TLC indicated that all the starting material had reacted, and it was then poured into a solution of sodium hydrogenocarbonate (2% w/v, 60 mL). This mixture was extracted with ether (4 x 30 mL). The combined ether extracts woe washed with water (2 x 30 mL), dried (magnesium sulfate), and evaporated, giving yellowish crystals (8.275 g, 68%) that were recrystallized twice from dichlorometbane petroleum ether to give colorless crystals of 14 yield 5.735 g (47%), mp 73J-74.5°C, [a]D-ll° (c 2.027, methanol). 

The V and A A series in the mass spectra of 2-deoxy-D- glucose" diethyl dithioacetal and L-rhamnose diethyl dithioacetal are shifted 14 mass units,... 

Hough, L, Taha, M I, The disulphones derived by oxidation of 2-amino-2-deoxy-D-glucose diethyl dithioacetal hydrochloride and its A-acetyl derivative with peroxypropionic acid, J. Chem. Soc., 3564-3572, 1957. 

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. 

Amino groups in dithioacetals undergo normal substitution reactions. Conventional reactions have been reported to occur with acetic anhydride,88,90,91 benzoyl chloride,46,92 l-fluoro-2,4-dinitrobenzene,250 p-toluenesulfonyl chloride,247 and benzyloxycarbonyl chloride92 the reported92 application of sodium chloride and methyl iodide to the conversion of 2-amino-2-deoxy-D-glucose diethyl dithioacetal hydrochloride into a pentamethyl derivative is presumed to be an error. Although crude 2-acetamido-2-deoxy-D-glucose diethyl dithioacetal was in one instance converted in low yield into a poorly... 

Benzyl 1-thio-lactoside and ethyl lactoside, prepared from lactose dibenzyl dithioacetal116 by the preceding methods, are necessarily pyranosides (owing to the substitution on 0-4). Stevens and coworkers310 prepared ethyl 2,3 4,5-di-0-isopropylidene-l-thio-/3-D-glucoseptanoside by partial demercaptalation of 2,3 4,5-di-O-isopropylidene-D-glucose diethyl dithioacetal. 

MacDonald and H. O. L. Fischer372 oxidized D-glucose diethyl dithioacetal pentaacetate (24) and its D-manno isomer with mono-peroxyphthalic acid in ether, isolating not the epimeric disulfones but a common product, to which they assigned the structure 3,4,5,6-tetra- O - acetyl -1,2- dideoxy-1,1 -bis (ethylsulfonyl)-D-arabtno-hex-1-enitol (176). Ammonolysis of 176 and reacetylation afforded 177, which was also prepared by oxidation of 2-acetamido-3,4,5,6-tetra-0-acetyl-2-deoxy-D-glucose diethyl dithioacetal, whereas the action of hydrazine in methanol on 176 produced a retroaldol reaction (and saponification) affording D-arabinose (179, 40% yield) and bis(ethyl-sulfonyl)methane (178). The latter reaction accords with earlier ob-... 

Isobutane-mediated chemical ionization (c.i.) of D-glucose diethyl dithioacetal produces408 initially an unstable proton-capture ion... 

The sirupy diethyl dithioacetal iV-methyl derivative of this compound was obtained by methylation of 2-amino-2-deoxy-D-glucose diethyl dithioacetal with dimethyl sulfate in dioxane solution. ... 

Displacements Catalyzed by Adds.—The acid-catalyzed mercaptala-tion reaction with ethanethiol normally leads to the aldose diethyl dithio-acetal, but, in anhydrous reaction media, further ethylthio substituents may be introduced into the molecule, usually at C-2. Brigl and coworkers found that ethanethiol and hydrogen chloride convert 3,4,5,6-tetra-O-benzoyl-D-glucose diethyl dithioacetal into 3,4,5,6-tetra-O-benz-oyl-2-)S-ethyl-2-thio-D-glucose (mannose) diethyl dithioacetal. The diethyl... 

---