The syntheses have been described of the 2-acetamido-2-deoxy derivatives of 5-thio-D-glucose lm3, 5-thio-D-mannose 4, 5-thio-D-allose 5, 3-acetamido-3-deoxy5thio-D-xylose6, and 4-acetamido-4-deoxy-5-thio-r_-lyxose6.
We now report the syntheses of 3-amino-3-deoxy-5-thio-D-allose hydrochloride and a derivative of the g&o analogue.
Treatment of the syrupy ketone7 1 with hydroxylamine in pyridine-ethanol gave two products which were separated by chromatography. The first was identified tentatively as the oxime 2, the structure of which was based on the 'H NMR data (Table I). Reduction of 2 with lithium aluminium hydride in dry ether gave a single product identified as 3-amino-3-deoxy-1,2-O : 5,6-S,O-di-isopropylidene-5-thio+Dallofuranose (3). The 'H NMR spectrum of 3 (Table I) showed some resemblance to that of the allo alcohol7 4.
Treatment of 3 with toluene-p-sulphonyl chloride in dry pyridine gave the crystalline N-tosylate 5 (58%). The corresponding acetamido (7) and benzamido (8) derivatives were obtained as syrups.
Hydrolysis of 3 in hot aqueous hydrochloric acid gave crystalline 3-amino-3-deoxy-5-thio-D-allose hydrochloride (91, the mutarotation of which [ -12" + + 65" (HZ011 indicated the @pyranose form, and this was confirmed by the conversion into the penta-acetate 10. The 'H NMR spectrum of 10 (Table I) demonstrated the 4C, conformation (J,,, 9.0, J4> 10.0 Hz).