ACS: Sweet surrender
I went to the carbohydrate-protein interactions and glycolipids session this morning (I’m at the ACS, in case you forgot). It was a great session! Even with the best efforts from the session chair, there were so many questions that we got way behind (which unfortunately meant that I missed George Wang’s talk due to a previous engagement). One particularly interesting part of the morning was yet another tribute to Emil Fischer, who seems to have done more work in his life than occurs in a year at most universities. In this particular story, Jacqueline Gervay-Hague was discussing the troubles with substituting sugars at the alpha position, and had tried to use trimethylsilyl iodine in combination with an alcohol to activate the center and incorporate the alcohol as a substituent. To her amazement, her student didn’t form the ester, but instead purified the iodated sugar. They looked back in the literature for any precedent of stable iodo-substituted sugars, and found that Fischer not only made them, but crystallized them back in 1910. The secret? The alpha-substituted sugar is stable, whereas the beta-functionalized position reacts right away. They have since used this insight to couple unprotected lipids to TMS-protected sugars; with the right purification conditions, they get the unprotected final product in one step.
Catherine Goodman (Assistant Editor, Nature Chemical Biology)