Two years ago, we were working on determining the stereochemistry of some sphingolipid analogs. To this end, we corresponded several times with Prof. Luigi-Gomez Paloma from Salerno, Italy to seek his help in implementing a pulse sequence to determine 2 and 3 bond HMBC coupling constants. We were already aware of his pioneering efforts to compute stereochemistry by comparing experimental and calculated coupling constants using the mPW1PW91 density functional. Later, he also worked on calculating and comparing C13 NMR shifts for finding stereochemistry.
While the project fell through, he was quite helpful. I became acquainted with his work, and was quite happy to see Scott Rychnovsky use the same technique and functional in his work on hexacyclinol. While K C Nicolaou does not explicity say it, I suspect he used the same functional in his recent revision of the structure of maitotoxin. For reference, I still have a mail or two from Prof. Gomez-Paloma.
So it can be imagined what I must have felt when, completely unexpectedly, I saw a simple sentence on top of Nicolaou's recent paper.
"In memory of Luigi-Gomez Paloma"Wow. That was unexpected and an unexpected way of getting to know it. Sad news.
Here are two of his pioneering papers. 1 (coupling constants) and 2 (C13 shifts). Prof. Gomez-Paloma was a talented organic chemist and an expert in NMR. He was definitely most instrumental in giving synthetic chemists the confidence to use quantum chemical NMR calculations to determine stereochemistry of natural products.
No comments:
Post a Comment
Markup Key:
- <b>bold</b> = bold
- <i>italic</i> = italic
- <a href="http://www.fieldofscience.com/">FoS</a> = FoS