51897-83-7Relevant articles and documents
Protected Aminooxazolines of Arabinose and Ribose
Cech, D.,Koenig, J.,Koeppel, H.,Moeller, S.
, p. 747 - 754 (2007/10/02)
The reaction of D-arabinose or D-ribose with cyanamide afforded 2-amino-1,2-oxazolines 1 which were treated with dihydropyran or ethylvinylether.In the presence of PTS the 3',5'-di-THP- or 3',5'-di-O-ethoxyethyl-D-arabino-(ribo)-furo--2-oxazolines 2 and 3 could be isolated as useful intermediates for the preparation of nucleosides.When the 2-aminooxazolines are treated with benzyloxycarbonylchloride or its p-substituted derivatives the N-3 atom of the oxazoline ring is preferentially substituted.Under these conditions the exocyclic amino function is always replaced and 2-oxo-3-benzyloxycarbonylderivatives 4 are obtained; only traces of the corresponding 2-aminoderivatives 5 are formed.Treatment of 4 with acetic anhydride, benzoylchloride, and benzoylcyanide, respectively, results in the 3'-,5'-di-O-acylderivatives 6.Mild hydrolysis of the benzyloxycarbonyl group with trifluoroacetic acid yields the 3',5'-di-O-acyl-D-arabino-(ribo)-furo--2-oxooxazolidines as further intermediates for the synthesis of nucleosides.