Bicyclic nucleoside synthesis: a photochemical approach.
The synthesis of a series of bicyclic nucleosides using photolytic ring-expansion of cyclobutanones is reported. The cyclobutanone precursors were prepared by [2+2] cycloaddition of a series of cyclic alkenes with chlorinated ketenes, derived from dichloro- and trichloroacetyl chloride. The synthesis of the nucleosides was achieved through photolysis of cyclobutanone precursors with 6-chloropurine by UV irradiation. The generality of this method was investigated and the absolute stereochemistry was assigned by NMR spectroscopy. The photoproducts demonstrated a marked preference for the 2'-exo conformation.
Department of Chemistry, York University, Toronto, Ontario, Canada.
E
E
Lee-Ruff
D
D
Wells
D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D015195:Drug Design; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D010777:Photochemistry; D010782:Photolysis; D013237:Stereoisomerism
D001643:Bridged Bicyclo Compounds; D009705:Nucleosides