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Nitrogen Derivatives of 1,6-Anhydrohexopyranoses

Nitrogen Derivatives of 1,6-Anhydrohexopyranoses 1. Amino and Azido Derivatives [Pg.121]

Another method, based on cyclization of glycosyl fluorides,764,765 such as 143 (for a methyl glycoside as a side-product, see Ref. 766), or of 6-O-p-tolylsulfonyl derivatives of hexoses95,97 (145), in alkaline media, was used for the preparation of 2-amino-1,6-anhydro-2-deoxy-/3-D-glucopyranose and its N-substituted derivatives (144). [Pg.122]

A quite different approach was demonstrated in the preparation of 2,4-diamino-1,6-anhydro-2,4-dideoxy-/J-D-talopyranose (147) from 146 by the action of phenylhydrazine and iodine, followed by catalytic reduction.433 [Pg.122]

Ammonolysis of l,6 3,4-dianhydro-2-0-benzyl-/3-D-galactopyran-ose (188) affords the 4-amino-4-deoxy derivative.740 It was also used for the preparation of the 2-amino-4-fluoro- and 4-amino-2-fluoro-2,4-dideoxy derivatives of l,6-anhydro-/3-D-glucopyranose.381 The oxirane ring of most dianhydrides is readily split not only by ammonia but also by its derivatives, such as methylamine, dimethylamine,320,7 7 and benzylamine.635 [Pg.124]

The course of ammonolysis of 111 is rather complicated, and the reaction results in a mixture containing 2,4-diamino-l,6-anhydro-2,4-dideoxy-j8-D-glucopyranose756 (154) (compare Ref. 513) and 1,6-an-hydro-3,4-dideoxy-3,4-epimino-/3-D-altropyranose756 (153) as the major products. This reaction course may be most satisfactorily explained by the sequence 111— 151 152, where 4-amino-1,6 2,3-dianhydro-4-deoxy-/3-D-mannopyranose (152) partly isomerizes (see Sect. VI,2) to the epimine 153, and partly reacts with ammonia to give740 the diamino derivative 154. [Pg.124]


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