98813-82-2

Upstream product

• 70988-61-3 tert-Butyl 5-methyl-3-(2-methoxycarbonylethyl)-4-methoxycarbonylmethylpyrrole-2-carboxylate 
• 121103-61-5 t-butyl 5-cyanomethyl-3-(2-methoxycarbonylethyl)-4-methoxycarbonylmethylpyrrole-2-carboxylate 
• 101210-29-1 5-Chloromethyl-3-(2-methoxycarbonyl-ethyl)-4-methoxycarbonylmethyl-1H-pyrrole-2-carboxylic acid tert-butyl ester 
• 121103-62-6 5-(Chloro-cyano-methyl)-3-(2-methoxycarbonyl-ethyl)-4-methoxycarbonylmethyl-1H-pyrrole-2-carboxylic acid tert-butyl ester 
• 603-35-0 triphenylphosphine 

Relevant academic research and scientific papers

Synthetic Studies Relevant to Biosynthetic Research on Vitamin B12. Part 9. Synthesis of 20-Methyl and 20-Cyano Isobacteriochlorins

Isobacteriochlorins carrying a C-methyl group at C-20 of the macrocycle are important for research on the biosynthesis of vitamin B12.Several different approaches are studied which allow the introduction of a C-20 methyl group into model isobacteriochlorins, the most successful involving the stepwise reduction of a nitrile residue to a methyl group.Successful syntheses are described of two 20-methylisobacteriochlorins and two 20-cyanoisobacteriochlorins.All the routes used depend finally on the photochemical cyclisation of an 18?-electron open-chain precursor.