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Synthesis 1998; 1998(1): 94-98
DOI: 10.1055/s-1998-4480
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Chirale Kronenether mit integriertem 1,4-verbrückten d-Glucopyranose-Baustein

Ralf Miethchen* , Volker Fehring
  • *Universität Rostock, Fachbereich Chemie, Organische Chemie, Buchbinderstraße 9, D-18051 Rostock, Germany; Fax + 49(3 81)4 98 17 63; E-mail: ralf.miethchen@chemie.uni-rostock.de
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Publication History

Publication Date:
31 December 2000 (online)

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Carbohydrate-Based Crown Ethers Containing 1,4-Linked d-Glucopyranose Moieties

The chiral crown ethers 7, 8, 9, and 13 containing a 1,4-bridged α-d-glucopyranose moiety were synthesized from methyl 2,3,6-tri-O-benzyl-α-d-glucopyranoside (1) and methyl 2,3-di-O-allyl-6-O-benzyl-α-d-glucopyranoside (2), respectively, by two subsequent etherification reactions followed by an intramolecular transglycosylation. To build up the hexaethylene glycol chain in 4-position of 1 and 2, bis(2-chloroethyl) ether (generating 3 and 4, respectively) and tetraethylene glycol (yielding 5 and 6, respectively) were used. The cyclizations of 5 and 6 in acetonitrile to the crowns 7 and 8 were catalysed by trimethylsilyl trifluoromethanesulfonate assisted by a "template" effect of potassium tetrafluoroborate (yield 45-57%). A high α-stereoselectivity was found for the intramolecular glycosylations even if a benzoylated precursor such as 12 was cyclized (catalyst: BF3 ⋅ Et2O; yield 25-26%). Compound 12 was prepared from 5 by exchange of the benzyl groups for benzoyl functions (10-12). Finally, the crown ether 8 was deallylated to generate the crown 9.

carbohydrates - pyranoses - d-glucose - crown ethers - chiral macrocycles

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