Reaktionen und Synthesen einiger natürlicher Amino‐hydroxysäuren

Wieland, Theodor

doi:10.1002/ange.19600722304

Cited by 10 publications

(1 citation statement)

References 48 publications

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“…In fact, the synthesis of threonine diastereomers by aldol-type condensation of acetaldehyde with the enolates of glycine equivalents is well described in the literature. [76,77] The question is just to choose the route with the best enantiomeric/diastereomeric excess. The yield is not so important, because the starting materials are inexpensive and the chiral auxiliary or catalyst should be recycled.…”

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Total Synthesis of Various Hormaomycin Analogues with Modified Amino Acid Residues

Raev¹

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AM 250 (250 MHz), Varian Unity 300 (300 MHz), Inova 500 (500 MHz), Inova 600 (600 MHz). 1 H chemical shifts are reported in ppm relative to residual peaks of deuterated solvents: δ (ppm) = 2.49 for [D 5 ]DMSO, 4.65 for HOD in D 2 O, 7.26 for CHCl 3 , 1.73 and 3.55 for [D 7 ]THF, 3.35 for CHD 2 OD. Higher-order NMR spectra were approximately interpreted as first-order spectra, if possible. For the characterization of the observed signal multiplicities the following abbreviations have been applied: s = singlet, d = doublet, t = triplet, q = quartet, quin = quintet, m = multiplet, as well as b = broad. 13 C NMR [additional DEPT (Distortionless Enhancement by Polarization Transfer) or APT (Attached Proton Test)]: Bruker AM 250 (62.9 MHz), AMX 300 (75.5 MHz) or Varian Unity 300 (75.5 MHz), Inova 500 (125.7 MHz), Inova 600 (125.7 MHz) instruments. 13 BORWIN HSS-2000, column Nucleodur ® C18 (250 mm × 20 mm, 5 µm, 100 Å), flow rate 18.0 ml/min. Optical rotations: Perkin-Elmer 241 digital polarimeter, 1-dm cell; optical rotation values are given in 10 -1 deg cm 2 g -1 ; concentrations (c) are given in g/100 mL. M.p.: Büchi 510 capillary melting point apparatus, uncorrected values. TLC: Macherey-Nagel pre-coated sheets, 0.25 mm Sil G/UV254. The chromatograms were viewed under UV light and/or by treatment with phosphomolybdic acid (10% in ethanol), or ninhydrine (0.2% in ethanol), or I 2 vapor. Column chromatography: Merck silica gel, grade 60, 230-400 mesh and Baker silica gel, 40-140 mesh. Elemental analyses: Mikroanalytisches Laboratorium des Instituts für Organische und Biomolekulare Chemie der Universität Göttingen.Starting materials: Anhydrous solvents were prepared according to standard methods by distillation over drying agents and were stored under nitrogen. All other solvents were distilled before use.All reactions were carried out with magnetic stirring and, when employing air-or moisturesensitive materials, in flame-dried glassware under argon or nitrogen. 7.General synthetic protocols Deprotection of N-Fmoc-protected peptides (GP 1)The respective protected peptide (1 mmol) was taken up with acetonitrile or THF (2 mL), diethylamine (2 mL) was added, and the resulting mixture left at ambient temperature for 40 min. All volatiles were evaporated under reduced pressure, the residue was taken up with toluene (2 × 5 mL), which was evaporated under reduced pressure to remove the last traces of diethylamine. The obtained crude N-deprotected peptide was directly used in the next condensation step. Peptide condensation step for the preparation of peptides using EDC/HOAt -mediated coupling (GP 2)EDC (1.03 mmol) and HOAt (1.05 mmol) were added to a cooled (4 °C) solution of the respective N-protected amino acid (1 mmol) in anhydrous CH 2 Cl 2 (3 mL). After 20 min, the solution of the appropriate crude N-deprotected peptide (0.97 mmol) and TMP (3 mmol) in

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Total Synthesis of Various Hormaomycin Analogues with Modified Amino Acid Residues

Raev¹

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Aminoalkohole, XIX. Synthese von α‐Amino‐γ‐hydroxysäuren über Isoxazolin‐carbonsäuren‐(3)

Drefahl¹,

Hörhold²

1964

Chem. Ber.

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Durch Cycloaddition von Oxalsaure-athylester-nitriloxyd an verschiedene Olefine werden Isoxazolin-carbons~ure-(3)-ester erhalten, die durch Verseifung und reduktive Ringspaltung in a-Amino-y-hydroxysiuren ubergefuhrt Hterden.a-Amino-y-hydroxysiiuren kommen in freier Form wie auch als Bestandteil von Peptiden in der Natur vor 2). In den letzten Jahren wurde in zunehmendem M a k uber die Auffindung neuer Vertreter in biologischem Material berichtet, so daD Untersuchungen uber Synthesen und chemische Eigenarten dieser Substanzklasse von Interesse erscheinen.

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Giftstoffe des grünen Knollenblätterpilzes (Amanita phalloides)

Wieland¹

1961

Helvetica Chimica Acta

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Volumen XLIV, Fasciculus IV (1961) -No. 105-106 919 Desglucocheirotoxol. 7 mg Desglucocheirotoxin wurden nach fruherer V o r~c h r i f t~~) rnit 1 mg NaBH, reduziert. Das Rohprodukt (4,8 mg) zeigte mit H,SO, praktisch gleiche Farbung wie Convallatoxol. Im Pch (System von Fig. 5) gab es nur einen Fleck mit Laufstrecke wie F". Die Mikroanalyse wurde unter der Leitung von Herrn E. THOMMEN im Mikrolabor des Instituts ausgefuhrt.

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Reaktionen und Synthesen einiger natürlicher Amino‐hydroxysäuren

Abstract: Professor Dr. Richard Kuliii zum 60. Gehurfsfag gewidmet Vorkommen, chemische Reaktionen und Synthesen einiger alter und neu entdeckter Amino-und Imino-hydroxysauren werden zusammenfassend besprochen.

Cited by 10 publications

References 48 publications

Total Synthesis of Various Hormaomycin Analogues with Modified Amino Acid Residues

Total Synthesis of Various Hormaomycin Analogues with Modified Amino Acid Residues

Aminoalkohole, XIX. Synthese von α‐Amino‐γ‐hydroxysäuren über Isoxazolin‐carbonsäuren‐(3)

Giftstoffe des grünen Knollenblätterpilzes (Amanita phalloides)

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