Note on the Preparation of Dibenzoyl-d-tartaric Acid

Butler, C. L.; Cretcher, Leonard H.

doi:10.1021/ja01333a507

Cited by 58 publications

(5 citation statements)

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“…Template Synthesis (Series A) (Scheme ). S - and R -1-amino-2-phenylethylphosphonate ( 1S and 1R ) were synthesized following the procedures by Oleksyszyn et al and Kafarski et al The diastereomers were separated by converting into tartrate salts and fractional crystallization . The amino group was protected using bis- tert -butoxycarboxylic anhydride ( 2S ) and converted to the diethyl ester ( 3S ) using triethylorthoformate and then to the monoester ( 4S ) by alkaline hydrolysis.…”

Section: Methodsmentioning

confidence: 99%

Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2^,

2000

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Highly cross-linked network polymers prepared by molecular imprinting catalyzed enantioselectively the hydrolysis of N-tert-butoxycarbonyl phenylalanine-p-nitrophenyl ester (BOCPheONP). The templates were designed to allow incorporation of the key catalytic elements, found in the proteolytic enzyme chymotrypsin, into the polymer active sites. Three model systems were evaluated. These were constructed from a chiral phosphonate analogue of phenylalanine (series A, C) or L-phenylalanine (series B) attached by a labile ester linkage to an imidazole-containing vinyl monomer. Free radical copolymerization of the template with methacrylic acid (MAA) and ethylene glycol dimethacrylate (EDMA) gave a highly cross-linked network polymer. The templates could be liberated from the polymers by hydrolysis, giving catalytically active sites envisaged to contain an enantioselective binding site, a site complementary to a transition state like structure (series A, C), and a hydroxyl, imidazole, and carboxylic acid group at hydrogen bond distance. As predicted, the enantiomer of BOCPheONP complementary to the configuration of the template was preferentially hydrolyzed with D-selectivity for the series A polymers (kD/kL = 1.9) and L-selectivity for the series B polymers (kL/kD = 1.2). The maximum rate enhancement, when compared with a control polymer, prepared using a benzoyl-substituted imidazole monomer as template, was 2.5, and comparing with the imidazole monomer in solution, a maximum rate enhancement of 10 was observed. The catalytic activity was higher for polymers subjected to the nucleophilic treatment. This was explained by a higher site density and flexibility of the polymer matrix caused by this treatment. In a comparison of template rebinding to polymers imprinted with a template containing either a carboxylate (planar ground state structure) or a phosphonate (tetrahedral transition state like structure) functionality, it was observed that imprinted polymers are able to discriminate between a transition state like and a ground state structure for transesterification. However the influence of transition state stabilization on the observed rate enhancements remains obscure. Only at acidic pH's was catalysis observed, whereas at basic pH's the polymers inhibit the reaction. At a later stage, the catalytic activity of the polymers for nonactivated D- and L-phenylalanine ethyl esters was investigated. A rate enhancement of up to 3 was observed when compared to the blank. Most important, however, the polymers imprinted with a D template preferentially hydrolyzed the D-ethyl ester and exhibited saturation kinetics.

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Section: Methodsmentioning

confidence: 99%

Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2^,

2000

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“…(1S)-()-Camphanic chloride (2a) was from Aldrich. Optically pure acid chlorides of monomethyl diacetyltartrate (2b) [17], monomethyl dibenzoyltartrate (2c) [18] and of monomethyl dipivaloyltartrate (2d) [19] were synthesized from L-tartaric acid (Aldrich). Optical rotatory powers of monomethyl diacyltartrates (2b-d) were correlated with literature values.…”

Section: Experimental Chemicalsmentioning

confidence: 99%

Comparative study on separation of diastereomers by HPLC

et al. 2003

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SummaryReversed (RP-HPLC) and normal phase chromatographic (NP-HPLC) separations have been developed for cliastereomers of N-acyl-l-methyl-l,2,3,4-tetrahydo-13-carbohnes which are acylatecl derivatives of simple natural 13-carbohne alkaloids. Separations of derivatives having different acyl moieties in the O,O-cliacyl-tartaric acid ester subtituent differed remarkably. Little or no resolution in either NP-HPLC or RP-HPLC could be achieved with the cliacetyl-tartrate derivative. Base-line separation by RP-HPLC but no separation by NP-HPLC was possible with the bulkier and more apolar clipivaloyl derivative. Retention order of the bis-benzoylatecl cliastereomers was reversed and separation time increased dramatically by RP-HPLC. Good separation of the medium polarity, but rigid, N-camphanyl derivative by NP-HPLC has been achieved, whereas RP-HPLC could not be used for separation of these cliastereomers. Separability of different cliastereomers was highly dependent on polarity and rigidity of the clerivatizing N-acyl moieties. Conformational analysis by molecular mechanics and comparison of the lowest energy conformational states of the cliastereomers was applied to rationahse separation-retention behaviou r of stereoisomers by RP-H PLC.

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“…(2) The deuterium in the products is found exclusively in the pivalate 20 and is specifically located at the C-3 position in the alkyl chain. Together with the above fact, the results indicate that each dioxane has undergone an intramolecular [1,5] hydrogen migration.…”

Section: Scheme I 17 18mentioning

confidence: 99%

Sigmatropic rearrangement of unsaturated acetals. Mechanistic study of the thermal isomerization of 5-alkylidene-1,3-dioxanes

Mutterer¹,

Fleury²

1974

J. Org. Chem.

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Note on the Preparation of Dibenzoyl-d-tartaric Acid

Abstract: Notes 2605The method is in constant use in this Laboratory. Although the procedure is long, it is actually less cumbersome to manipulate than the standard method and much more certain in its results.

Cited by 58 publications

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Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2^,

Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2^,

Comparative study on separation of diastereomers by HPLC

Sigmatropic rearrangement of unsaturated acetals. Mechanistic study of the thermal isomerization of 5-alkylidene-1,3-dioxanes

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Note on the Preparation of Dibenzoyl-d-tartaric Acid

Abstract: Notes 2605The method is in constant use in this Laboratory. Although the procedure is long, it is actually less cumbersome to manipulate than the standard method and much more certain in its results.

Cited by 58 publications

References 0 publications

Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2,

Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2,

Comparative study on separation of diastereomers by HPLC

Sigmatropic rearrangement of unsaturated acetals. Mechanistic study of the thermal isomerization of 5-alkylidene-1,3-dioxanes

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Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2^,

Enantioselective Ester Hydrolysis Catalyzed by Imprinted Polymers. 2^,