Thank you Joerg for your Kind effort.

I want to know either any researcher synthesize himself in the laboratory or not.

In the literature i already read Nos of references.

Once again thanks to reply my Question and you gave your precious time to me

Total synthesis of vitamin B12 developed by Robert B. Woodward (Harvard University) and Albert Eschenmoser (ETH Zürich) completed by more than 100 of postdoctorals during ~ 13 years. To control the stereochemistry is quit difficult task. I suggest you look at the CLASSICS IN TOTAL SYNTHESIS I, II and III written by Nicolaou and coworkers. So far total preparation of B12 have not been completed by anybody else.

Thank you respected Nosrat for upgrade my Knowledge.

I didn't see anywhere too, not a single report. I myself actually need the answer. if u find sth new plz tell me too.

Sure if i got it, will be share with you

Hamidreza Hajfarajollah i Found the following link you can check it

http://www.synarchive.com/syn/71

Nowadays, it is produced by fermentation.

Thanks dear friend :)

That seems very good!

Thanks Allah Who gave us the chance to play our role for explore this universe.