Synthesis of the three isomeric mono-2-, 3-, or 6-hydroxy permethylated β-cyclodextrins and unambiguous high field NMR characterisation

Cousin, H.; Cardinaël, Pascal; Oulyadi, Hassan; Pannecoucke, Xavier; Combret, Jean‐Claude

doi:10.1016/s0957-4166(00)00499-7

Cited by 28 publications

(8 citation statements)

References 27 publications

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“…After methylation of the remaining six 3-hydroxy groups, the desired product 9 was obtained in 90% yield after purification. A shorter route to 7 was investigated starting from 2 IϪVII ,3 IϪVI ,6 IϪVII -eicosa-O-methylcyclomaltoheptaose, but neither the use of a different base [52] nor the use of 8-iodo-1-octene (prepared starting from 8-bromo-1-octene) were successful. The known low reactivity of the hydroxy group in the O-3 position could explain why the reaction does not (7) occur.…”

Section: Resultsmentioning

confidence: 99%

“…For the preparation of 2 IϪVI ,3 IϪVII ,6 IϪVI -eicosa-Omethyl-2 I -O-(oct-7-enyl)cyclomaltoheptaose (6), a method similar to the one described for the second route to compound 4 was used, starting from 2 IϪVI ,3 IϪVII ,6 IϪVII -eicosa-O-methylcyclomaltoheptaose (5), [52] which resulted in 6 being obtained in 75% yield (cf. Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

“…Purification of the residue by column chromatography (silica gel, toluene/acetone, 4:1) and recrystallization from n-heptane gave 4 (920 mg, 0.60 mmol) in 87% yield. IϪVI -eicosa-O-methylcyclomaltoheptaose (3) (500 mg, 0.35 mmol), which was prepared by adapting the procedure of Bradshaw and co-workers, [50,52] in anhydrous THF (20 mL) was added dropwise to a stirred mixture of sodium hydride (17 mg, 0.70 mmol, washed with THF) in anhydrous THF (10 mL Figure 6. Gas chromatographic separation of the enantiomers of neomenthol (3,4), menthol (5,6), and isomenthol (7,8) in the presence of the reference standards n-dodecane (1) and n-tridecane (11,12), and 2-ethylhexanoic (13,14) in the presence of the reference standards n-undecane (9) and ndodecane (10) and O-2-Chirasil-β-Dex (bottom) (carrier gas: dihydrogen; for additional gas chromatographic data, see Table 5) …”

Section: Methodsmentioning

confidence: 99%

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Synthesis, NMR Spectroscopic Characterization and Polysiloxane‐Based Immobilization of the Three Regioisomeric Monooctenylpermethyl‐β‐cyclodextrins and Their Application in Enantioselective GC

Cousin¹,

Trapp

Peulon-Agasse³

et al. 2003

Eur J Org Chem

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2I−VI,3I−VII,6I−VII‐Eicosa‐O‐methyl‐2I‐O‐(oct‐7‐enyl)cyclomaltoheptaose, 2I−VII,3I−VI,6I−VII‐eicosa‐O‐methyl‐3I‐O‐(oct‐7‐enyl)cyclomaltoheptaose, and 2I−VII,3I−VII,6I−VI‐eicosa‐O‐methyl‐6I‐O‐(oct‐7‐enyl)cyclomaltoheptaose were synthesized by selective introduction of an oct‐7‐enyl group at one of the O‐2, O‐3, or O‐6 positions of selectively methylated cyclomaltoheptaose (β‐cyclodextrin, CD) and, depending on the synthetic route, by a subsequent permethylation step. Each of the regioisomeric mono‐oct‐7‐enylated permethylated β‐cyclodextrin derivatives was anchored by hydrosilylation to a hydridomethyldimethylsiloxane copolymer to yield unambiguously O‐2‐, O‐3‐, and O‐6‐bonded chiral stationary phases (CSP) of Chirasil‐Dex, which were evaluated in enantioselective gas chromatography (GC). O‐6‐Chirasil‐Dex displayed slightly inferior enantioselectivity relative to either O‐3‐ or O‐2‐Chirasil‐Dex. The statistical synthesis of the CSP by mono‐oct‐7‐enylation of β‐CD under varying reactions conditions (base, solvent), without the use of hydroxy group protection chemistry, furnished a mixture of O‐6‐ and O‐2‐Chirasil‐Dex in dimethylformamide and predominantly the O‐2‐regioisomer in dimethyl sulfoxide. Chirasil‐Dex, previously formulated exclusively as the O‐6 regioisomer, should be revised as an O‐2‐ and O‐6‐Chirasil‐Dex mixture. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Synthesis, NMR Spectroscopic Characterization and Polysiloxane‐Based Immobilization of the Three Regioisomeric Monooctenylpermethyl‐β‐cyclodextrins and Their Application in Enantioselective GC

Cousin¹,

Trapp

Peulon-Agasse³

et al. 2003

Eur J Org Chem

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“…The monosubstituted derivative 18 was prepared in good yield by reaction of the tritylated imidazole 7 with monohydroxy compound 17 in the presence of sodium hydride ( Scheme 3 ) [ 35 ]. The 1 H NMR signals of the diastereotopic methylene protons in product 18 were respectively observed at 4.57 and 4.71 ppm, while the corresponding 13 C signal connected to the aromatic group was detected at 67.0 ppm.…”

Section: Resultsmentioning

confidence: 99%

Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

Letort¹,

Bosco²,

Cornelio³

et al. 2017

Beilstein J. Org. Chem.

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New derivatives of cyclodextrins were prepared in order to determine the relative importance of the structural key elements involved in the degradation of organophosphorus nerve agents. To avoid a competitive inclusion between the organophosphorus substrate and the iodosobenzoate group, responsible for its degradation, the latter group had to be covalently bound to the cyclodextrin scaffold. Although the presence of the α nucleophile iodosobenzoate was a determinant in the hydrolysis process, an imidazole group was added to get a synergistic effect towards the degradation of the agents. The degradation efficiency was found to be dependent on the relative position of the heterocycle towards the reactive group as well as on the nature of the organophosphorus derivative.

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“…In this report, the hydroxy group at the 2-position of 2II-VII, 3I-VII, 6I-VII-Icosa-O-acetyl-2I-deoxy-cyclomaltoheptaose 1-prepared by monobenzylation at the 2-position, followed by acetylation [13][14][15]-was substituted with hydrogen via Barton-McCombie deoxygenation. The synthesis procedure and data for the synthesized compound (3) are reported herein.…”

Section: Introductionmentioning

confidence: 99%

2II-VII, 3I-VII, 6I-VII-Icosa-O-acetyl-2I-deoxy-cyclomaltoheptaose

Miyagawa

Kano

Yoshida

et al. 2016

Molbank

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Synthesis of the three isomeric mono-2-, 3-, or 6-hydroxy permethylated β-cyclodextrins and unambiguous high field NMR characterisation

Cited by 28 publications

References 27 publications

Synthesis, NMR Spectroscopic Characterization and Polysiloxane‐Based Immobilization of the Three Regioisomeric Monooctenylpermethyl‐β‐cyclodextrins and Their Application in Enantioselective GC

Synthesis, NMR Spectroscopic Characterization and Polysiloxane‐Based Immobilization of the Three Regioisomeric Monooctenylpermethyl‐β‐cyclodextrins and Their Application in Enantioselective GC

Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

2II-VII, 3I-VII, 6I-VII-Icosa-O-acetyl-2I-deoxy-cyclomaltoheptaose

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