Nucleotides. Part XXXVII. The structure of uridylic acids a and b, and a synthesis of spongouridine (3-β-D-Arabofuranosyluracil)

Abstract

Monoacetylation of 5'-O'-acetyluridine yields a crystalline diacetate, from which by phosphorylation with dibenzyl phosphorochloridate followed by removal of protecting groups uridylic acid a is obtained. The diacetate is shown to be 3': 5'-Di-O-acetyl-2'-O-toluene-p-sulphonyluridine → O²: 2'-cyclouridine → 3-β-D-arobofuranosyl. Uridylic acid a is, therefore,uridine-2' phosphate. 3-β-D-Arobofuranosyl-uracil is identical with spongouridine, a nucleoside occuring naturally in sponges.