Abstract
Epistephanine (I : R=CH3), an alkaloid of Stephania japonica Miers and its dimethiodide (IV), on hydrogenation, did not yield racemic compounds but optically active ones in either case. Epistephanine (I : R=CH3), on hydrogenation with zinc and sulfuric acid, afforded only hydroepistephanine-A (II) as the dihydro derivative. Treatment of (II) with methyl iodide gave N-methylhydroepistephanine-A dimethiodide (III), which was shown by direct comparison of their specific rotations and infrared spectra to be identical with O-methyloxyacanthine dimethiodide (III)(asymmetric centers, +, -). Epistephanine dimethiodide (IV), when reduced with either sodium borohydride or zinc-sulfuric acid, afforded N-methylhydroepisephanine monomethiodide, from which N-methylhydroepistephanine-B dimethiodide (VI) was derived. It was found that (VI) is identical with O-methylrepandine dimethiodide (IX)(asymmetric centers, +, +) by infrared spectral determinations, and that since the values of their specific rotations have the opposite sign to each other, (VI) is an antipode of (IX) and hence its asymmetric centers are (-, -).
