**A Convenient Synthesis of Leucovorin** The synthesis of leucovorin, a 5‐formyl‐(6__R__ or __S__)‐5,6,7,8‐tetrahydropteroyl‐L‐glutamic acid (II) is described. The L‐folic acid was first reduced to (6__R__, __S__)‐tetrahy‐dro‐L‐folic acid (I); formylation with methyl‐formate in DMSO gave directly l
Über Pterinchemie 75. Mitteilung Synthese von 7-Aminoxanthopterin
✍ Scribed by Konrad Baumgartner; Jost H. Bieri
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- German
- Weight
- 345 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Synthesis of 7‐Aminoxanthopterin
7‐Aminoxanthopterin (II) is obtained in good yield and purity by the transformation of isomer‐free xanthopterin‐7‐carboxylic acid (I) with NH~3~ followed by oxidation with MnO~2~. The Frontier Orbital Theory contributes to a better understanding of the reaction pathway.
📜 SIMILAR VOLUMES
**The crystal structure of xanthopterine‐hydrochloride.** The crystal structure of the title compound, a pterine, has been determined by X‐ray analysis (direct methods) and refined with 1332 structure amplitudes to __R__ = 0.027. The crystal system is monoclinic, space group __P__2~1/__c__~, with u
**On the pathway of the catalytic reduction of 6,7‐diphenylpterin** The pathway of the hydrogen addition to the pyrazine ring of 6, 7‐diphenylpterin (**1a**) during acid‐catalyzed reduction was elucidated. Initial hydrogenation of the 5, 6‐double bond produces 6, 7‐diphenyl‐5, 6‐dihydropterin (**2a
**Conformational Analysis of Acylated 5,6,7,8‐Tetrahydropterines** The conformation of __N__(5)‐acetates, and of __N__(5)‐ and __N__(8)‐trifluoroacetates, respectively, of 6‐methyl‐ and __cis__‐6, 7‐dimethyl‐tetrahydropterines is studied by ^1^H‐NMR. spectroscopy. It is shown that the methyl group
**On the Pathway of the Catalytic Reduction of 7‐Methylpterin** The catalytic hydrogenation of 7‐methylpterin (VII) in a neutral solution occurs first by the reduction of the 7,8‐double bond (thermodynamically‐controlled reaction) followed by the reduction of the 5,6‐double bond. On the contrary, i
## Abstract Eine neue Synthese des Biopterins ausgehend von L‐4‐Methyl‐erythrulose und 2,4,5‐Triamino‐6‐hydroxy‐pyrimidin wird beschrieben. Bei der Oxydation des intermediär gebildeten Tetrahydrobiopterins wird die Dihydroxypropyl‐Kette so leicht abgespalten, dass die Ausbeute an Biopterin auch bei