J. Hill, L. Hough
Dec 1, 1968
Citations
0
Influential Citations
16
Citations
Journal
Carbohydrate Research
Abstract
Abstract Methyl 2-acetamido-3- O -acetyl-2-deoxy-4,6-di- O -methanesulphonyl-α- D -glucopyranoside ( 1 ) undergoes displacement of both sulphonate groups with sodium benzoate in N , N -dimethylformamide to give, after saponification, methyl 2-acetamido-2-deoxy-α- D -galactopyranoside ( 5 ), thereby providing a convenient synthesis of this galactosamine derivative. The 6-methanesulphonate group of compound 1 is very easily replaced by a chlorine atom when treated with pyridinium chloride in pyridine, so that the 6-chloro derivative ( 2 ) is encountered as a by-product in the preparation of compound 1 . The disulphonate also undergoes displacement with the thiocyanate anion to give the corresponding 4,6-dithiocyanato-galactopyranoside 6 , together with the disulphide 7 derived from the dithiocyanate by hydrolysis followed by oxidative ring-closure. The desulphurisation of either of these derivatives gives, after hydrolysis, 2-amino-2,4,6-trideoxy- D - xylo -hexose hydrochloride ( 11 ).