Biosynthesis of vitamin B12: regio-control in peripheral C-methylation of 20-methylpyrrocorphins carrying ester side chains
Abstract
Mild methods are developed for the predominant generation of D-pyrrocorphins from 20-methyldihydroisobacteriochlorins carrying ester side chains; the corresponding zinc(II) 20-methyl-D-pyrrocorphinates undergo methylation preferentially at C-17.