Preparation of dicyano- and methylcobinamide from vitamin B12a.

[摘要]：Treatment of vitamin B12a (hydroxycobalamin HCl, aquocobalamin) with NaBH4 and ZnCl2 leads to the selective cleavage of the nucleotide loop and gives dicyanocobinamide in good yield. Methylcobinamide was prepd. from the latter via aquocyanocobinamide. The subsequent glutathione-mediated methylation in a pH 3.5 buffer soln. proceeded with MeI, but not with MeO3SC6H4-4-Me.

[全文传递流程]：

一般上传文献全文的时限在1个工作日内