Miescher degradation

What is Miescher degradation?

 

The Miescher degradation is a modified version of the Barbier-Wieland degradation technique that enables the elimination of three carbon atoms simultaneously. This is particularly useful in the degradation of bile acid side chains to their methyl ketone stage.

To achieve this, the methyl ester of the bile acid is first converted to a tertiary alcohol, which is then subjected to a series of chemical reactions including dehydration, bromination, dehydrohalogenation, and oxidation of the diene. These reactions ultimately yield a ketone that has been shortened by removal of three carbon atoms from the original chain.

Miescher degradation
Miescher degradation

References

Meystre, C., Frey, H., Wettstein, A. and Miescher, K. (1944), Über Steroide. (39. Mitteilung). Ein einfacher Abbau der Gallensäuren-Seitenkette zur Methylketonstufe. [On steroids. (39th Announcement). A simple degradation of the bile acid side chain to the methyl ketone stage.] Helvetica Chimica Acta, 27: 1815-1824. https://doi.org/10.1002/hlca.194402701230

 

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