Nucleoside moiety of vitamin B12, q.v. Isoln by acid hydrolysis of vitamin B12: N. G. Brink et al., J. Am. Chem. Soc. 72, 1866 (1950); N. G. Brink, K. Folkers, ibid. 74, 2856 (1952). Syntheses of α- and β-anomers: F. W. Holly et al., ibid. 4521; R. S. Wright et al., ibid. 80, 2004 (1958); J. D. Stevens et al., J. Org. Chem. 33, 1806 (1968). Biosynthetic study: J. H"orig, P. Renz, FEBS Lett. 80, 337 (1977). Spectroscopic characterization: K. L. Brown et al., Inorg. Chem. 23, 1463 (1984).