title: Ring-Opening of 3-beta-D-ribofuranosyl-3,7,8,9-Tetrahydropyrimido [1,2-i]purin-8-ol and preparation of 2-thio- and 2-aza-adenosine derivatives.
abstract: The adduct 3-beta-D-ribofuranosyl-3,7,8,9-tetrahydropyrimido[1,2-i]purin-8-ol (2), obtained from adenosine and epichlorohydrin, underwent ring fission at basic conditions. The initial ring-opening took place at C2 of the pyrimidine unit resulting in 2-(5-amino-1-beta-D-ribofuranosyl-imidazol-4-yl)-1,4,5,6-tetrahydropyrimidin-5-ol (3). Also the tetrahydropyrimidine ring of 3 could be opened resulting in 5-amino-1-(beta-D-ribofuranosyl)-imidazole-4-(N-3-amino-2-hydroxyl-propyl)-carboxamide (4). In hot acid conditions, 2 was both deglycosylated and ring-opened yielding 2-(5-amino-imidazol-4-yl)-1,4,5,6-tetrahydropyrimidin-5-ol (7) as the final product. When reacting 3 with CS(2) or HNO(2) ring-closure took place and 3-beta-D-ribofuranosyl-3,4,7,8,9-pentahydropyrimido[1,2-i]purin-8-ol-5-thione (5), and 3-beta-D-ribofuranosyl-imidazo[4,5-e]-3,7,8,9-tetrahydropyrimido[1,2-c][1,2,3]triazine-8-ol (6), respectively, were obtained. Also, the pyrimidine ring of the epichlorohydrin adduct with adenine, 10-imino-5,6-dihydro-4H,10H-pyrimido[1,2,3-cd]purin-5-ol (10), underwent ring fission and the product was identified as 3-hydroxy-1,2,3,4-tetrahydroimidazo[1,5-a]pyrimidine-8-carboximidamide (11).
authors.affiliation: Laboratory of Organic Chemistry, Abo Akademi University, Turku, Abo, Finland.
authors.forename: Pernilla
authors.initials: P
authors.lastname: Sund
authors.forename: Leif
authors.initials: L
authors.lastname: Kronberg
mesh_terms: D000241:Adenosine / Q000737:chemistry*; D018736:DNA Adducts / Q000138:chemical synthesis / Q000737:chemistry*; D004811:Epichlorohydrin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure
chemical_list: D018736:DNA Adducts; D004811:Epichlorohydrin; D000241:Adenosine