Saturday, September 5, 2009

Tamiflu

A new strain of swine flu, an H1N1influenza virus, is spreading around the globe. The WHO has declared the novel H1N1 influenza virus (swine flu - 2009) outbreak a global pandemic - First Phase 6 Influenza pandemic since 1968.



(_)-Oseltamivir phosphate (Tamiflu), a neuraminidase inhibitor used to treat both type A and type B human influenza. Currently, it is the most effective drug for the treatment of Influenza. However, the unmet supply of this drug demands urgent solutions. The manufacture of Tamiflu by Roche Company utilizing naturally occurring shikimic acid as the starting material. Getting stable quality of pure shikimic acid may be problematic. 

The Tamiflu supply problem has piqued the attention of academic chemists. Several labs have already reported new methods for making Tamiflu without shikimic acid. However, it is challenging to evaluate academic syntheses from the standpoint of potential as a manufacturing process because they have not been developed for large-scale operation. Considering the amount of Tamiflu required worldwide, there is an urgent demand to improve the production process.


Here is the retrosynthetic analysis for the shortcut synthesis of Tamiflu. This synthesis initiated by oxa-Michael addition of alcohol to acrolin, which was reported by Zhang et al,