27085-12-7Relevant academic research and scientific papers
Rare α-alkyl isomers of cobalamins: Synthesis, characterization, and properties of two diastereomers of the α-alkylcobalamin, α-(2-oxo-1,3-dioxolan-4-yl)cobalamin
Alelyunas, Yun W.,Fleming, Paul E.,Finke, Richard G.,Pagano, Thomas G.,Marzilli, Luigi G.
, p. 3781 - 3794 (2007/10/02)
The synthesis, characterization, 2-D NMR (HOHAHA, NOESY, HMQC, and HMBC spectroscopies), and reactivities of a new α-alkylcobalamin are described (an α-alkylcobalamin has the axial alkyl group attached to the cobalt from the bottom or α face of the corrin ring). The α-alkylcobalamin, α-(2-oxo-1,3-dioxolan-4-yl)cobalamin (1), is the first example of an α-alkylcobalamin with a secondary alkyl group and the first case with a chiral alkyl group (i.e., where α-alkylcobalamin diastereomers are produced). It is also the first α-alkylcobalamin completely characterized (HPLC, UV-visible, IR, FAB-MS, and 1- and 2-D NMR methods). Anaerobic photolysis converts 1 to its β isomer, β(2-oxo-1,3-dioxolan-4-yl)cobalamin (2), where the alkyl group is now attached to the cobalt from the usual, β or top side of the corrin. Physical properties previously unavailable for any α-alkylcobalamin were measured for 1, notably the β-side axial base binding constants [for 1-methylimidazole, pyridine, (±)-histidine, and 1,5,6-trimethylbenzimidazole], and the thermal stability of the individual diastereomers of 1. Possible mechanisms for, and the factors controlling, the formation of α- and β-alkylcobalamins are presented and discussed.
