Zur Konflguration der Shikimisäure (7. Mitteilung über Chinasäure und Derivate)

Abstract

zeigte nach einmaligem Cmkrystallisieren am Essigester-Ligroin den Smp. l.57--15S0 und gab mit einem Vergleichspraparat keine Depression. 4,769 mg Subst. gaben 7,190 mg CO, und 1,990 nig H,O CGH,0,(1i6) Ber. C 40,9 H 4 , 5 O , Gef. ,, 41,l ,, 4,io,I n fast gleicher Ausbeute, aber mit niedrigerem Schmelzpunkt erhielten wir die Aconitsaure in einem entsprechend durchgefuhrten Ansatz mit f r e i e r Shikimisaure'). Bis-2,i-dinitrophenylhydrazon d e s A c o n i t s i i u r e -m et h y l e s t e r -d i a l d e h y d s . Der bei dem Abbau des Shikimisjure-methylesters 2, mit zwei 3101 Perjodshure entstehende Dialdehyd kann aus der von Jodsiiure und Silberion befreiten Losung mit zn-ei 3101 2,4-Dinitrophenylhydrazin in salzsaurer Losung gut als Bis-2,4-dinitrophenylhydrazon gefallt werden. Rohausbeute 75 yo der Theorie. Zur Reinigung in kaltem Pyridin gelost, mit gleichen Teilen Essigester verdiinnt und durch Zufugen von Alkohol krystallinisch ausgefiillt. Smp. 169O. 5,240 mg Subst. gaben 8,500 mg CO, und 1,540 mg H,O. 2,967 mg Subst. gaben 0,557 cm3 N, (25O und 758 mm) 2,551 mg Subst. gaben 1,160 mg AgJ(OCH, schwer veneifbar) C

Solution conformations of three small cluster oligosaccharide mimetics (SCOM) from D-glucosamine, D-altrosamine, and (-)-quinic acid

“…NOEDIF experiments. Approximately 10 mg of the compound was dissolved in CDCl 3 and was subjected to three freeze-thaw cycles in liquid nitrogen with evacuation/N 2 -flushing on a Schlenk line while frozen. NOEDIF spectra were recorded nonspinning for 512 transients at room temperature on a 300 MHz Varian Mercury system.…”

“…The cyclohexane ring B of 6 had been shown 13 by analysis of 3 J-values to exist to a significant extent in an unusual twist-boat solution conformation in CDCl 3 in both anomers (Table 1). However, the exact overall solution conformation of the whole molecule had not been determined and only minimal molecular modeling data were discussed.…”

“…Quinic acid (1, Figure 1) 1 and its derivative shikimic acid (2, Figure 1) [2][3][4] (from Illicium japonica and floridanum) are key intermediates during the biochemical synthesis of essential aromatic amino acids, such as L-tryptophan, L-phenylalanine, and L-tyrosine in plants, bacteria, and fungi as well as building blocks for folic acid, alkaloids, and vitamins. The quinic acid/shikimic acid pathway does not exist in mammals, which has led to extensive research activities geared towards the development of suitable antibiotic therapeutics.…”

Synthesis of Glycosylrifamycins, a new type of semisynthetic rifamycins

“…79 (1996) (12), which was then oxidized to the S form 13. Analogously, 2 was reacted with the 3,4-O-isopropylidene derivative of shikimic acid [ 121 to give rifamycin SV derivative 14 and, after oxidation, its S form 15.…”

Structure of sodium (–)-shikimate dihydrate

“…by Eijckmann (1885). Its structure was established by Fischer & Dangschat (1934, 1935 and the absolute stereochemistry derived by degradation and correlation with glucose derivatives (Fischer & Dangschat, 1937). The conformation of the cyclohexene ring in solution was shown to be a half-chair by NMR spectroscopy (Hall, 1964).…”