Quinidine isomerides

There is also for the quinidine ether oxide group (formula C) an im-expected third isomeride, possibly due to epimerisation about carbon atoms 9 and 10. These quinidine isomerides are no doubt convertible... 

The isomeride quiienidine, similarly produced by the oxidation of quinidine, crystallises in prisms, m.p. 246°, [a]f ° -(- 258° (A -H jS04), and, like quitenine, gives quininic and cincholoiponic acids by further oxidation. 

In the cases of quinine and quinidine there is an additional complication, except for reaction (c), owing to partial de-methylation of the methoxyl group, thus in the action of sulphuric acid on quinine there may be four products of formula E, viz., the two geometrical isomerides apoquinine and isoapoquinine (for which Q is 6-hydroxyquinolyl) and their methyl ethers, j8-isoquinine and a-isoquinine respectively (for which Q is 6-methoxyquinolyl). 

It will be seen from the foregoing that there is no systematic nomenclature for these compounds. Some of them have been isolated by several workers and with the impression that they were new substances have been given new names, and this applies especially to the two isocinchonines and dihydrocinchonine. It will be noticed that instead of the two geometrical isomerides required by formula (Ga) there are three cinchon-hydrines. The a- and jS-forms are well-defined crystalline substances, but the supposed y-form (see table, p. 452) is amorphous and its authenticity doubtful. Eormula (E) requires two geometrical isomerides, but quinidine... 

Quinicine (quinotoxine), 419,425, 442,448 Quinidine, 419, 424 configuration, 443 constitntion, 435 isomerides, 453-4 pharmacological action, 479 transformaticn products 448 Quinidine, 419, 4 ... 

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