Partielle Substitution der 1,6-Anhydro-β-D-glucopyranose

Černý, M.; Gut, V.; Pacák, J.

doi:10.1135/cccc19612542

Cited by 74 publications

(14 citation statements)

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“…149°C (ref. [24] 148-150°C Cuprate Addition to Epoxide 3, General Procedure: A suspension of CuCN (4 equiv.) in freshly distilled dry diethyl ether was treated under argon at -78°C with a solution of the respective organolithium compound (8 equiv.)…”

Section: 6:34-dianhydro-2-o-tolylsulfonyl-β-d-galactopyranose (3)mentioning

confidence: 99%

“…[10] An example for one of the best investigated routes to the dimethyl compound 4 proceeds through the selective di-tosylation of 1 to produce the monoalcohol 2, which is cyclized to the "Č erný" epoxide 3. [24] This epoxide was converted in three steps to the 2,4-dideoxy-2,4-dimethyl-1,6-anhydro-β-d-glucopyranose derivative 4 by reaction with methylmagnesium chloride in the presence of catalytic amounts of cuprous bromide or iodide (Normant cuprate, Scheme 1). [20,25] The regioselectivity of the nucleophilic attack is controlled by the Fürst-Plattner Scheme 1. a) TsCl, acetone/pyridine, 1:1, 2 h, 0°C, 71 %; b) NaOMe, CH 2 Cl 2 , 2 h, room temp., 92 %; c) MeMgCl (4 equiv.…”

Section: Introductionmentioning

confidence: 99%

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New Derivatives of Levoglucosan by Tandem Epoxide Allyl Alcohol Rearrangement‐Cuprate Cross‐Coupling

Krohn¹,

Gehle²,

Flörke³

2005

Eur J Org Chem

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Keywords: 1,6-Anhydro sugars / Chiral building blocks / Branched sugars / Č erný epoxide / Gilman cuprates / Epoxide rearrangement / Vinyl tosylate cross couplingThe alkylated allyl alcohols 6a, 7, and 8 (R = Me, Et, nBu) were formed in the reaction of the Č erný epoxide 3 with the Cyano-Gilman cuprates. The one-pot reaction was initiated by base-catalyzed epoxide allyl alcohol rearrangement to compound 5, followed by unprecedented vinyl tosylate crosscoupling with the cuprates, to form the alkylation products 6a, 7, and 8. The allyl alcohol 6a was transformed into a

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Section: 6:34-dianhydro-2-o-tolylsulfonyl-β-d-galactopyranose (3)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New Derivatives of Levoglucosan by Tandem Epoxide Allyl Alcohol Rearrangement‐Cuprate Cross‐Coupling

Krohn¹,

Gehle²,

Flörke³

2005

Eur J Org Chem

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“…When the 3-and 6-position are tethered, for example by metal binding, the glucopyranose ring undergoes a ring flip, bringing together the 2-and 4-position as shown in Figure 1b. Levoglucosan is the ideal starting material for such transformations as the 2-and 4-positions can be functionalized with high regioselectivity via the Černý epoxide [20].…”

Section: Introductionmentioning

confidence: 99%

Easy access to a carbohydrate-based template for stimuli-responsive surfactants

Holmstrøm¹,

Raydan²,

Pedersen³

2020

Beilstein J. Org. Chem.

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In this paper we describe the synthesis of a new carbohydrate-based building block functionalized with azido or amino groups on the 2 and 4 positions. The building block can be synthesized in anomerically pure form in only five scalable steps starting from commercially available levoglucosan. It was shown that the building block could undergo alkylations under strongly basic conditions. The building block with azido groups could furthermore take part in CuAAC reactions, generating derivatives with ester or carboxylic acid functionalities. In addition, the anomeric mixture of the building block was used for the synthesis of a molecule that could act as an emulsifier only in the presence of Zn2+ ions.

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“…R f (cyclohexane/AcOEt 2 : 1) 0. 40 (2)); 2.12 (s, AcO). (1) (6) The mixture was allowed to warm to r.t. and stirred for 17.5 h. The resulting dark yellow soln.…”

mentioning

confidence: 99%

“…Ethylene glycol could not be completely replaced by another solvent, but treating 8 with 6 equiv. of KHF 2 and KF [44] in ethylene glycol/ diethylene glycol diethyl ether 1 : 1 for 1 h at 2008, followed by flash chromotography, yielded 43% of the desired fluoro diol 9, 12% of its regioisomer 10, and 3% of the dgulo epoxide 11 [40] [45]. The side products are the result of the known rearrangement of 8 to the isomeric epoxide 11 [40], and the transformation of 11 into the d-galactoconfigured fluoro diol 10.…”

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confidence: 99%

Hydrogen Bonding of Fluorinated Saccharides in Solution: F Acting as H‐Bond Acceptor in a Bifurcated H‐Bond of 4‐Fluorinated Levoglucosans

Bernet¹,

Vasella²

2007

Helvetica Chimica Acta

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4‐Fluorinated levoglucosans were synthesised to test if OH⋅⋅⋅F H‐bonds are feasible even when the O⋅⋅⋅F distance is increased. The fluorinated 1,6‐anhydro‐β‐D‐glucopyranoses were synthesised from 1,6 : 3,4‐dianhydro‐β‐D‐galactopyranose (8). Treatment of 8 with KHF2 and KF gave 43% of 4‐deoxy‐4‐fluorolevoglucosan (9), which was transformed into the 3‐O‐protected derivatives 13 by silylation and 15 by silylation, acetylation, and desilylation. 4‐Deoxy‐4‐methyllevoglucosan (19) and 4‐deoxylevoglucosan (21) were prepared as reference compounds that can only form a bivalent H‐bond from HOC(2) to OC(5). They were synthesised from the iPr3Si‐protected derivative of 8. Intramolecular bifurcated H‐bonds from HOC(2) to FC(4) and OC(5) of the 4‐fluorinated levoglucosans in CDCl3 solution are evidenced by the 1H‐NMR scalar couplings h1J(F,OH) and 3J(H,OH). The OH⋅⋅⋅F H‐bond over an O⋅⋅⋅F distance of ca. 3.0 Å is thus formed in apolar solvents, at least when favoured by the simultaneous formation of an OH⋅⋅⋅O H‐bond.

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Partielle Substitution der 1,6-Anhydro-β-D-glucopyranose

Cited by 74 publications

References 0 publications

New Derivatives of Levoglucosan by Tandem Epoxide Allyl Alcohol Rearrangement‐Cuprate Cross‐Coupling

New Derivatives of Levoglucosan by Tandem Epoxide Allyl Alcohol Rearrangement‐Cuprate Cross‐Coupling

Easy access to a carbohydrate-based template for stimuli-responsive surfactants

Hydrogen Bonding of Fluorinated Saccharides in Solution: F Acting as H‐Bond Acceptor in a Bifurcated H‐Bond of 4‐Fluorinated Levoglucosans

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