Addition of pseudohalogens to unsaturated carbohydrates. III. Synthesis of 3-deoxy-3-C-nitromethyl-D-allose, a branched-chain nitro sugar

1969 ◽  
Vol 47 (23) ◽  
pp. 4473-4476 ◽  
Author(s):  
W. A. Szarek ◽  
J. S. Jewell ◽  
I. Szczerek ◽  
J. K. N. Jones
Keyword(s):  
Sodium Borohydride ◽  
Wittig Reaction ◽  
Furanose Form ◽  
Acid Catalyzed ◽  
Branched Chain ◽  
Hydrolysis Of

Addition of nitryl iodide to 3-deoxy-1,2:5,6-di-O-isopropylidene-3-methylene-α-D-ribo-hexofuranose (2), followed by treatment of the product with sodium borohydride, gave crystalline 3-deoxy-1,2:5,6-di-O-isopropylidene-3-C-nitromethyl-α-D-allofuranose (3); the branched-chain unsaturated sugar (2) was prepared by way of a Wittig reaction with 1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose (1). Acid-catalyzed hydrolysis of 3 afforded 3-deoxy-3-C-nitromethyl-D-allose, which exists predominantly in the β-D-furanose form (4).

scholarly journals Facile synthesis of benzothiadiazine 1,1-dioxides, a precursor of RSV inhibitors, by tandem amidation/intramolecular aza-Wittig reaction

2013 ◽  
Vol 9 ◽  
pp. 503-509 ◽  
Author(s):  
Krishna C Majumdar ◽  
Sintu Ganai
Keyword(s):  
High Purity ◽  
Wittig Reaction ◽  
Facile Synthesis ◽  
The Core ◽  
Amide Derivatives ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Reaction of o-azidobenzenesulfonamides with ethyl carbonochloridate afforded the corresponding amide derivatives, which gave 3-ethoxy-1,2,4-benzothiadiazine 1,1-dioxides through an intramolecular aza-Wittig reaction. The reaction was found to be general through the synthesis of a number of benzothiadiazine 1,1-dioxides. Acid-catalyzed hydrolysis of 3-ethoxy-1,2,4-benzothiadiazine 1,1-dioxides furnished the 2-substituted benzothiadiazine-3-one 1,1-dioxides in good yields and high purity, which is the core moiety of RSV inhibitors.

scholarly journals Synthesis of olivomycose (2,6-dideoxy-3-C-methyl-L-arabino-hexose)

1969 ◽  
Vol 47 (23) ◽  
pp. 4467-4471 ◽  
Author(s):  
E. H. Williams ◽  
W. A. Szarek ◽  
J. K. N. Jones
Keyword(s):  
Wittig Reaction ◽  
High Yield ◽  
Lithium Aluminium Hydride ◽  
Ruthenium Tetroxide ◽  
Lithium Aluminium ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Oxidation of methyl 4,6–O-benzylidene-2-deoxy-α-L-arabino-hexopyranoside (1) with ruthenium tetroxide gave the 3-ketone 2 in high yield. A Wittig reaction between methylenetriphenylphosphorane and compound 2 gave methyl 4,6-O-benzylidene-2,3-dideoxy-3-C-methylene-α-L-erythro-hexopyranoside (3), which was hydrated by the oxymercuration–demercuration procedure to afford methyl 4,6-O-benzylidene-2-deoxy-3-C-methyl-α-L-arabino-hexopyranoside (4). The reaction of compound 4 with N-bromosuccinimide gave methyl 4-O-benzoyl-6-bromo-2,6-dideoxy-3-C-methyl-α-L-arabino-hexopyranoside (5) in high yield. Treatment of compound 5 with lithium aluminium hydride followed by acid-catalyzed hydrolysis of the resultant product, gave L-olivomycose (6).

Hydrogen generation from aqueous acid-catalyzed hydrolysis of sodium borohydride

2010 ◽  
Vol 35 (22) ◽  
pp. 12239-12245 ◽  
Author(s):  
Hyun Jae Kim ◽  
Kyoung-Jin Shin ◽  
Hyun-Jong Kim ◽  
M.K. Han ◽  
Hansung Kim ◽  
...  
Keyword(s):  
Sodium Borohydride ◽  
Hydrogen Generation ◽  
Aqueous Acid ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Branched-chain derivatives of acyclic adenosine analogs: Alkyl and hydroxymethyl derivatives of S-adenosyl-L-homocysteinase inhibitors substituted at the 2- and 3-position of the side chain

1989 ◽  
Vol 54 (1) ◽  
pp. 248-265
Author(s):  
Antonín Holý
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Borohydride ◽  
Sodium Salt ◽  
Osmium Tetroxide ◽  
Sodium Perchlorate ◽  
Side Chain ◽  
Isopropylidene Derivative ◽  
Branched Chain ◽  
Hydrolysis Of ◽  
Derivatives Of

Reaction of 1,3-dichloro-2-propanone (VII) with methylmagnesium chloride, followed by alkaline hydrolysis, afforded 2-methylpropane-1,2,3-triol (VIII) which on treatment with 2,2-dimethoxypropane and subsequent tosylation gave 4-(p-toluenesulfonyloxymethyl)-2,2,4-trimethyl-1,3-dioxolane (IXb). Compound IXb was condensed with sodium salt of adenine and the intermediate X was acid-hydrolysed to give 9-(RS)-(2,3-dihydroxy-2-methylpropyl)adenine (XI). Oxidation of XI with sodium periodate led to 9-(2-oxopropyl)adenine (XII). 9-(RS)-(2-Hydroxy-2-hydroxymethyloctyl)adenine (XVI) was obtained analogously from compound VII and hexylmagnesium bromide via triol XIV. Methyl 2-bromomethyl-2-propenoate (XVII) reacted with sodium salt of adenine and the resulting methyl 2-(adenin-9-ylmethyl)-2-propenoate (XVIII) was hydroxylated with sodium perchlorate and osmium tetroxide. The obtained methyl (RS)-2-(adenin-9-ylmethyl)-2,3-dihydroxypropanoate (XIX) was alkali-hydrolysed to give sodium salt of the acid XX. Reduction of ester XIX with sodium borohydride furnished 9-(RS)-(2,3-dihydroxy-2-hydroxymethylpropyl)adenine (XXI). 1-Nonen-3-ol (XXIII), obtained by reaction of propenal with hexylmagnesium bromide, was converted by hydroxylation with osmium tetroxide into nonane-1,2,3-triol (XXIVa) and further into its 1-O-p-toluenesulfonate XXIVb which reacted with 2,2-dimethoxypropane to give 2,2-dimethyl-4-hexyl-5-(p-toluenesulfonyloxymethyl)-1,3-dioxolane (XXV). Compound XXV reacted with adenine and the resulting intermediate XXVI was converted into 9-(RS)-(2,3-dihydroxynonyl)adenine (XXVII) by acid hydrolysis. 9-(3-Methyl-2-buten-1-yl)adenine (XXVIII), obtained by alkylation of sodium salt of adenine with 1-bromo-3-methyl-2-butene, was oxidized with potassium permanganate in an acid medium to give 9-(3-hydroxy-2-oxo-3-methylbutyl)adenine (XXIX). This compound was converted into 9-(RS)-(2,3-dihydroxy-3-methylbutyl)adenine (XXX) by reduction with sodium borohydride. 4-C-Hydroxymethyl-1,2-O-isopropylidene-α-D-xylofuranose (XXXII) reacted with 2,2-dimethoxypropane under formation of 4-C-hydroxymethyl-1,2:3,5-di-O-isopropylidene derivative XXXIIIa whose p-toluenesulfonyl derivative XXXIIIb on treatment with adenine afforded 4-C-(adenin-9-yl)methyl-1,2:3,5-di-O-isopropylidene-α-D-xylofuranose (XXXIV). Acid hydrolysis of this compound, followed by oxidation in an alkaline medium, gave (2S,3R)-4-(adenin-9-yl)-3-hydroxymethyl-2,3-dihydroxybutanoic acid, isolated as its ethyl ester XXXVI.

The effect of polymeric and model imidazolium halides on the rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid

1985 ◽  
Vol 50 (4) ◽  
pp. 845-853 ◽  
Author(s):  
Miloslav Šorm ◽  
Miloslav Procházka ◽  
Jaroslav Kálal
Keyword(s):  
Catalyst Concentration ◽  
Low Molecular Weight ◽  
Imidazolium Chloride ◽  
First Order ◽  
Nitrobenzoic Acid ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Hydrolysis Of ◽  
Ethanol In Water ◽  
Direct Attack

The course of hydrolysis of an ester, 4-acetoxy-3-nitrobenzoic acid catalyzed with poly(1-methyl-3-allylimidazolium bromide) (IIa), poly[l-methyl-3-(2-propinyl)imidazolium chloride] (IIb) and poly[l-methyl-3-(2-methacryloyloxyethyl)imidazolium bromide] (IIc) in a 28.5% aqueous ethanol was investigated as a function of pH and compared with low-molecular weight models, viz., l-methyl-3-alkylimidazolium bromides (the alkyl group being methyl, propyl, and hexyl, resp). Polymers IIb, IIc possessed a higher activity at pH above 9, while the models were more active at a lower pH with a maximum at pH 7.67. The catalytic activity at the higher pH is attributed to an attack by the OH- group, while at the lower pH it is assigned to a direct attack of water on the substrate. The rate of hydrolysis of 4-acetoxy-3-nitrobenzoic acid is proportional to the catalyst concentration [IIc] and proceeds as a first-order reaction. The hydrolysis depends on the composition of the solvent and was highest at 28.5% (vol.) of ethanol in water. The hydrolysis of a neutral ester, 4-nitrophenyl acetate, was not accelerated by IIc.

Benzyl ethers of methyl α-D-glucopyranoside

1980 ◽  
Vol 45 (7) ◽  
pp. 1959-1963 ◽  
Author(s):  
Dušan Joniak ◽  
Božena Košíková ◽  
Ludmila Kosáková
Keyword(s):  
Kinetic Study ◽  
Spectrophotometric Determination ◽  
Reductive Cleavage ◽  
Ether Bond ◽  
Benzyl Ethers ◽  
Acid Catalyzed ◽  
Model Substances ◽  
Hydrolysis Of

Methyl 4-O-(3-methoxy-4-hydroxybenzyl) and methyl 4-O-(3,5-dimethoxy-4-hydroxybenzyl)-α-D-glucopyranoside and their 6-O-isomers were prepared as model substances for the ether lignin-saccharide bond by reductive cleavage of corresponding 4,6-O-benzylidene derivatives. Kinetic study of acid-catalyzed hydrolysis of the compounds prepared was carried out by spectrophotometric determination of the benzyl alcoholic groups set free, after their reaction with quinonemonochloroimide, and it showed the low stability of the p-hydroxybenzyl ether bond.

Cyclization and acid-catalyzed hydrolysis of O-benzoylbenzamidoximes

1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský
Keyword(s):  
Reaction Rate ◽  
Kinetic Isotope ◽  
Acid Base Equilibrium ◽  
Mineral Acids ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Ph Scale ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Derivatives Of

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.

scholarly journals Application of Polyimide‐based Microfluidic Devices on Acid‐catalyzed Hydrolysis of Dimethoxypropane

2021 ◽  
Vol 93 (5) ◽  
pp. 796-801
Author(s):  
Jens Bobers ◽  
Elisabeth Forys ◽  
Bastian Oldach ◽  
Norbert Kockmann
Keyword(s):  
Microfluidic Devices ◽  
Acid Catalyzed ◽  
Hydrolysis Of
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