PolytheneSam (Master Searcher)
12-31-02 16:26
No 394599
      d,l-tartrate --> l-tartrate  Bookmark   

A way to make l-tartaric acid from the racemic form.  It still requires an organism.

Pasteur on the verge of fermentation

"Thus, there was a great interest in deciding whether racemic acid would undergo the same fermentation as the right tartrarte acid, in other words, whether the yeast would transform the left tartrate acid as readily and in the same way as the right tartrate acid. The ammonium racemate was fermented in the same manner as I indicated above for the right tartrate. The fermentation manifested itself as easily, with the same characteristics and deposit of yeast. But in following the development of this phenomenon with a polariser, it was clear that things are altogether different. After a few days of fermentation, the liquid that was at first inactive, now possesses a discernable rotatory power on the left, and this power increases progressively during the fermentation until it reaches a maximum. At which point fermentation is then stopped. There is not a trace remaining of right acid in the liquor which, once evaporated and mixed to its volume of alcohol, provides at once an abundant crystallisation of left ammoniac tartrate.

No doubt this offers an excellent means to prepare left tartrate acid. But the whole interest of this fact seems to me to depend on the physiological role of fermentation which appears, in my experiments, as a phenomenon pertaining to the vital order. We see here that the character of molecular dissymetry so peculiar to organic matters intervenes to modify the affinity. There is no doubt that it is the type of dissymmetry characteristic of the molecular arrangment of the left acid tartrate that is the only and exclusive cause of the non-fermentation of this acid in the very conditions where the symmetric acid is destroyed" (C.R. AC. des Sciences, sťance du 29 mars 1858, XLVI pp.615-618)


The hardest thing to explain is the obvious
(Master Searcher)
12-31-02 17:44
No 394610
      reversed?  Bookmark   

What if you used l-tartaric acid instead of the d- form?  Would the difference in solubilities between the d- and l- forms of amphetamine and methamphetamine tartrate be reversed?
../rhodium/chemistry /amphetamine.resolution.html

The hardest thing to explain is the obvious
(Hive Adickt)
01-01-03 17:29
No 394768
      yes  Bookmark