Improved preparation of methyl 4,6-O-benzylidene-α-D-glucopyranoside

In order to assess the effect of the antagonist methyl 4,6-dichloro-4,6-dideoxy-alpha-D-galactopyranoside (MAD-diCl-Gal) upon the gerbil's chorda tympani sucrose taste response, we tested several concentrations of this compound, as well as single concentrations of closely related derivatives, and found that MAD-diCl-Gal was the most potent inhibitor tested. It appears that the inhibition mechanism is very specific. For example, we have found that 2 chlorine atoms at the C-4 and C-6 positions on the glucopyranoside ring are required for inhibition. In addition, with regard to the orientation of the chlorine atoms, the galacto derivative seems to be more potent than the gluco derivative. We have also found that the methyl glycoside is more potent than the free sugar. With regard to the orientation of the methyl group, MAD-diCl-Gal is more potent than its beta-anomer. (Because of this discovery of the methyl group enhancement and orientation effect, we shall discontinue using the acronym diCl-Gal and replace it with the more specific MAD-diCl-Gal.) Of particular significance is the fact that there appears to be a structure-activity relationship between the most active stimulants and inhibitors in that the requirement for an axial orientation at C-1 and the enhancement by the methyl group at that position are the same in both cases. These results suggest that both the stimulator and the antagonist are acting at the same receptor site.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…Methyl 4,6-0-benzylidene-&&glucopyran&ide, hp = 165-166"c, [a]," = + 109" (C = 1.1, chloroform) (Van Cleve, 1971). , 1972).…”

Section: Methodsmentioning

confidence: 99%

A structure-activity study on the sucrose taste antagonist methyl 4,6- dichloro-4,6-dideoxy-alpha-D-galactopyranoside

Vlahopoulos¹,

Jakinovich²

1986

J. Neurosci.

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“…9 Alternatively, benzylidenation can be accomplished in high yield employing a benzylidene acetal, in the presence of a Lewis acid such as ZnCl 2 , or via a Brønsted acid catalyst. [10][11][12][13][14][15] Recent studies have examined alternative methodologies, including the use of ultrasonics, 16 lanthanide cation-exchange resins, 17 tin(II) triflates, 18 and microwave 19 assisted benzylidenation of carbohydrates.…”

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confidence: 99%

“…42 Indeed, in most cases, the optimal ionic liquid provided the desired 4,6-O-benzylidene in comparable or enhanced yields than have been reported for conventional organic solvents. [10][11][12][13][14][15]43 In addition, we tested the recycling properties of ionic liquids employed in this study. In brief, upon completion of benzylidenation and extraction of the products, the ionic liquids were quantitatively recycled by washing with toluene, water, and then filtered through a pad of Celite.…”

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confidence: 99%

Synthesis of benzylidenated hexopyranosides in ionic liquids

Zhang¹,

Ragauskas²

2005

Carbohydrate Research

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Oxaphosphoranylation of Methyl α‐d‐Glucopyranoside with Diethoxytriphenylphosphorane: Highly Stereoselective Approach to Anhydropyranosides

Eskew¹,

Evans²

1990

Heteroatom Chemistry

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Diethoxytriphenylphosphorane (DTPP) efficiently oxaphosphoranylates methyl α‐d‐glucopyranoside to afford two unstable isomeric 1,3,2λ5‐dioxaphospholanes. Thermolysis (60–90°C) of these 1,3,2λ5‐dioxaphospholanes affords only two of four possible isomeric anhydropyranosides. Two distinct intermediate betaines and their unique “pre‐transition state” chair or twist‐boat structures are used to rationalize the regiochemistry‐attending cyclodehydration. The decomposition of these rapidly interconverting 1,3,2λ5‐dioxaphospholanes is accelerated in the presence of lithium bromide (LiBr) to afford a single anhydropyranoside.

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Improved preparation of methyl 4,6-O-benzylidene-α-D-glucopyranoside

Cited by 19 publications

References 2 publications

A structure-activity study on the sucrose taste antagonist methyl 4,6- dichloro-4,6-dideoxy-alpha-D-galactopyranoside

A structure-activity study on the sucrose taste antagonist methyl 4,6- dichloro-4,6-dideoxy-alpha-D-galactopyranoside

Synthesis of benzylidenated hexopyranosides in ionic liquids

Oxaphosphoranylation of Methyl α‐d‐Glucopyranoside with Diethoxytriphenylphosphorane: Highly Stereoselective Approach to Anhydropyranosides

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