Werner Döpke

Neue Amaryllidaceen-Alkaloide

The ca lcula t ions h a v e now been e x t e n d e d for t he elucida t ion of t he compos i t ion of t he complex ion fo rmed in t h e s y s t e m : A g B r K C N S H z O , a n d t h e d a t a r epor t ed b y RA~])aLL a n d HALFO~D a) ut i l ized for th i s purpose . These a u t h o r s have p o s t u l a t e d t h e fo rmula of t h e compl ex a n d h a v e conf i rmed the i r pos tu Ia t ed fo rmula indirect ly . I t will be seen t h a t our m e t h o d leads to t h e direct ca lcu la t ion of t he s toichiome t ry , w i t h o u t a n y pr ior a s s u m p t i o n of t h e composi t ion .

Zwei schwefelhaltige Alkaloide aus einer kongolesischen Baumrinde

*) GR6OER, D., U. K. STOLLE: Naturwissenschaften ~1, 637 (1964). ~) GORMAN, iV[., N. NEUSS, O.H. SVOBODA, A. J . BARNESS jr, u. N.I. CONE: J. Am. Pharm. Assoc., Set. Ed. 48, 256 (t959). 3) MOZA~ t3. K., J . TROJANEK, V. HANUS U. L. DOLEJ~: Collection Czechoslov. Chem. Commun. 29, 1913 ( t 9 6 4 ) . a)BIE~AXN, K.: a) Mass. Spectrometry. New York: McGraw Hill 1962; b) Ind. ehim. belge 1962, t319.

The Absolute Configuration of the Poppy Alkaloid Nudaurine

Abstract The poppy alkaloid, nudaurine, was shown by X-ray crystallography to have an (S)-configuration at C-7 opposite to the configuration previously assigned by oxidative degradation.

Chapter 2 The Eburnamine-Vincamine Alkaloids

Publisher Summary The alkaloids eburnamine from Hunteria eburnea Pichon and vincamine from Vinca minor are the prototypes of the indole alkaloid class eburnaminevincamine. The alkaloids of this class are derivatives of ring skeletons of the same constitution. The absolute configurations of alkaloids belonging to this series have been established and progress has been made in clarifying the relative and absolute stereochemistry of several. NMR spectroscopy and mass spectrometry have proved useful tools in the structure analysis of certain eburnamine-vincamine alkaloids, although, yet, neither has been utilized extensively.