2-AMINO-7-Β-D-ARABINOFURANOSYL-4-MEYHOXY-7H-PYRROLOPYRIMIDINE: A FACILE PREPARATION AND ANOMERISATION OF A 7-DEAZAPURINE NUCLEOSIDE

Article abstract of DOI:10.1016/0008-6215(83)88032-X

Phase-transfer glycosylation of 2-amino-4-methoxy-7H-pyrrolo<2,3-d>pyrimidine with 2,3,5-tri-O-benzyl-D-arabinofuranosyl bromide in benzene-50percent aqueous sodium hydroxide-tetrabutylammonium hydrogensulfate gave two anomeric glycosylation products (1 and 3).Removal of the benzyl groups from 1 and 3, respectively, with boron trichloride yielded 2-ami-no-7-(α- and β-D-arabinofuranosyl)-4-methoxy-7H-pyrrolo<2,3-d>pyrimidine(4 and 2).Treatment of 2 and 4 with 2M hydrochloric acid under nitrogen caused anomerisation and demethylation without glycosylic cleavage, and reflected the extraordinary stability of pyrrolo<2,3-d>pyrimidine nucleosides towards hydrolisis.The conversion of 2 and 4 into ara-7-deazaguanosine or its α anomer was accomplished with anhydrous acid.