Die Konformationen vielgliedriger Ringe

Dale, Johannes

doi:10.1002/ange.19660782403

Cited by 67 publications

(18 citation statements)

References 199 publications

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“…2). On the other hand, the latter group has no such dose (7) Non-bonded distanees of the former group around C(1)A-C(1)B is 68° corresponding to a graMCÄe-conformation of the two CH2's and that of the latter group around C(8)A-C(8)B is 177° corresponding to an aw<i-conformation (DALE, 1966). But both twisting angles are shifted away from the strain-free values (60° and 180°) by few degrees.…”

Section: Reflnementmentioning

confidence: 98%

The crystal and molecular structure of [2₄] metacyclophane I

UEDA¹,

NOWACKI²

1974

Zeitschrift Für Kristallographie - Crystalline Materials

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AuszugRöntgenographisch wurden zwei Modifikationen von [24]-Metacyclophan gefunden. Die Kristallstruktur der Form I wurde mittels dreidimensionaler Daten bestimmt. Die Raumgruppe ist f 2i/c; die Gitterkonstanten sind a = 10,180, b = 23,375, c = 5,074 Ä und ß = 105 = 31'. Die Elementarzelle enthält zwei zentrosymmetrische Moleküle. Die Intensitätsdaten wurden mit Hilfe eines automatischen Diffraktometei'S gesammelt und die Ausgangsstruktur wurde mittels einer symbolischen Additionsmethode erhalten. Der Ä-Endwert für alle 2224 Reflexe war 10,1 ®/o. Im Molekül sind die Cyclophaneinheiten abwechslungsweise durch gaiiche-und anii-Konformation verbunden und mit den anderen Einheiten durch van der Waalsche Abstände in Kontakt. Die zwei CH2-Gruppen des einen verbindenden Paares in der asymmetrischen Einheit vibrieren entlang der c*-Achse anisotrop viel stärker als diejenigen des anderen äquivalenten Paares. Die Moleküle berühren sich über normale van der Waalscho Abstände. AbstractTwo modifications were found in [24] metacyclophane by an x-ray diffraction method. The crystal structure of one of these modifications, [24] metacyclophane I, was determined from three-dimensional x-ray diffraction data. The Space group is P2i/c and the cell dimensions are a = 10.180, b = 23.375, c = 5.074 Ä and ß = 105°3r. The unit cell contains two molecules and the molecule has a centre of symmetry. The intensity data were collected by an automated diffractometer and the initial structure was solved by a symbolic addition method. The final disagreement factor for all 2224 refiections was 10.

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Section: Reflnementmentioning

confidence: 98%

The crystal and molecular structure of [2₄] metacyclophane I

UEDA¹,

NOWACKI²

1974

Zeitschrift Für Kristallographie - Crystalline Materials

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“…Techniques are required which permit the efficient, simultaneous cyclization of a large number of linear peptides without regard to their sequences, especially in the design and synthesis of cyclic peptide libraries [1,2]. D-and N-alkylated amino acids are known to be turn-inducing [7][8][9]. The presence of turninducing units should enhance the cyclization of these peptides by the formation of cyclization-prone conformations.…”

Section: Introductionmentioning

confidence: 99%

Influence of proline and β-turn mimetics on the cyclization of penta- and hexapeptides

Klose¹,

Ehrlich²,

Bienert³

1998

Lett Pept Sci

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Proline and Pro-derived peptidomimetics, such as meoxPro-Oic (4-methoxy-proline-octahydro indolic acid), and DBF (2-aminoethyl-6-dibenzofuran propionic acid) were introduced into thymopentin-derived penta-[SP5-] and hexa-[SP6-] peptides and penta-, hexa-and hepta-alanine. Surprisingly, we found that cyclomonomer formation in the investigated penta-and hexapeptides was drastically hindered by the presence of proline regardless of position.

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“…Transmission of conformational information across macrocyclic rings such as 14-membered macro-lactones has been demonstrated by Still and co-workers [6] and Weiler and co-workers [7]. The conformational transmission is aided by the fact that 14-membered rings have only few low-energy conformations [8]. This suggested to us that the recognition domain, the dihydroxypentanoyl unit of aplysiatoxin, could probably be conformationally controlled as well by incorporation into a much simpler 14-membered macro-dilactone such as 3, derived from 3,4-dihydroxypentanoic acid and an w-hydroxynonanoic acid [4] (Fig.…”

mentioning

confidence: 93%

Synthesis and Conformational Analysis of Macrocyclic Dilactones Mimicking the Pharmacophore of Aplysiatoxin

Knust

Hoffmann

2003

Helvetica Chimica Acta

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A small number of macrocyclic dilactones of type 3, i.e., 9, 10, 11, and epi-11, comprising a 3,4-dihydroxypentanoic acid unit, the pharmacophore of aplysiatoxin, and a conformationally preorganized whydroxynonanoic acid unit were synthesized. Conformational analysis ± based on 2 J and 3 J NMR coupling constants ± of the dihydroxypentanoyl part of these macro-dilactones indicates the extent to which a conformation induction across the macro-dilactone ring occurs from the stereogenic centres implemented in the w-hydroxynonanoic acid part.

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Die Konformationen vielgliedriger Ringe

Cited by 67 publications

References 199 publications

The crystal and molecular structure of [2₄] metacyclophane I

The crystal and molecular structure of [2₄] metacyclophane I

Influence of proline and β-turn mimetics on the cyclization of penta- and hexapeptides

Synthesis and Conformational Analysis of Macrocyclic Dilactones Mimicking the Pharmacophore of Aplysiatoxin

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Die Konformationen vielgliedriger Ringe

Cited by 67 publications

References 199 publications

The crystal and molecular structure of [24] metacyclophane I

The crystal and molecular structure of [24] metacyclophane I

Influence of proline and β-turn mimetics on the cyclization of penta- and hexapeptides

Synthesis and Conformational Analysis of Macrocyclic Dilactones Mimicking the Pharmacophore of Aplysiatoxin

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The crystal and molecular structure of [2₄] metacyclophane I

The crystal and molecular structure of [2₄] metacyclophane I