Mj. Pfammatter et al., SYNTHESIS OF VITAMIN-B12 DERIVATIVES WITH PERIPHERAL TRIS(OXYETHYLENE) CHAINS, Helvetica Chimica Acta, 81(6), 1998, pp. 1105-1116
The new derivatives 7a-c, of vitamin B-12, with a peripheral tris(oxye
thylene) chain linked to the corrin ring by an amide or ester group, a
re prepared, and their ligand-exchange reactions are investigated. Upo
n reduction of the aqua-cyano complexes 8a-c with NaBH4, cleavage of t
he 'outer' ester and amide group is observed.