A tribute to Albert Eschenmoser

Abstract

On December 24th 2015 I received on my desk the last issues 11/12 of Helvetica Chimica Acta combined in a most impressive single volume of 579 pages! I only had to turn a page to find a picture of Albert and Elisabeth Eschenmoser and another page opened to «Corrin Syntheses». So it had happened, what chemists had been longing for. Within the full description of the monumental studies on the synthesis of corrin-type compounds was enshrined a chemical jewel, the saga of the heroic total synthesis of Vitamin B12 (p. 1555 – 1574). The total synthesis of Vitamin B12 over the years from the beginning-1960ies to 1972, considered as a landmark achievement in the art and science of natural product synthesis, was a transatlantic effort involving the intimate collaboration of two groups, one at Harvard University led by Robert Burns Woodward and the other one at the Eidgenössische Technische Hochschule in Zurich (ETHZ) directed by Albert Eschenmoser. This joint effort was duly acknowledged in no unclear terms by Woodward both at the beginning and at the end of a lecture he gave at the Chemistry Department of Harvard University on November 27th 1972 and recorded in a film to be found on the Internet.1 The undersigned contributed to the work at Harvard University during his one year stay (October 1963 - September 1964) as post-doctoral co-worker in the laboratory of Woodward. The work done at Harvard will very probably never be published and has been described in printed form only in reports of lectures and in the movie mentioned above. It is therefore an all the more scientifically and historically most notable event to have the formidable work of the Eschenmoser group - the Harvard/ETHZ pathway towards the total synthesis of Vitamin B12 but also the ETHZ photochemical variant - now available in printed form, with a description of the lines of thought as well as of the hard work, the trepidation and the exhilaration lining the synthetic conquest of Vitamin B12 in full experimental details. It was hard to realize, but here it was in front of my eyes on December 24th 2015. I sent at once a message to Albert saying that it was indeed the greatest gift I could have hoped for! We must be deeply grateful to him for offering this gift, this gigantic achievement, this phenomenal tour-de-force, to all of us chemists, a testimony to the creative power of chemistry. I would also like to thank very warmly Dr. M. Volkan Kısakürek for editing and producing this scientific monument with his legendary care and expertise.