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Your search keyword '"Shendage, Deepak M."' showing total 12 results
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12 results on '"Shendage, Deepak M."'

1. The vinylfluoro group as an acetonyl cation equivalent: stereoselective synthesis of 6-substituted 4-hydroxy pipecolic acid derivatives

Author

Purkayastha, Nirupam, Shendage, Deepak M., Frohlich, Roland, and Haufe, Gunter

Subjects
Carboxylic acids -- Chemical properties, Carboxylic acids -- Structure, Hydrolysis -- Usage, Biological sciences, Chemistry
Abstract

An unprecedented cascade of reactions is described after acid-catalyzed hydrolysis of tert-butyl (2S,5S)-2-tert-butyl-5-(2-fluoroallyl)-3-methyl-4-oxoimidazolidine-1-carboxylate that has led to pipecolic acid derivatives. The pipecolic acid is used for preparing (2R,4R,6S)-6-tert-butyl-4-hydroxypiperidine-2-carboxylic acid.

Published
2010

3. ChemInform Abstract: Fries Rearrangement: Scalable Synthesis of Key Fluoro Building Blocks 3‐Fluoro‐4‐methoxybenzoyl Chloride (IV) and 1,2‐Diethoxy‐3‐fluorobenzene (V).

Author

Yerande, Swapnil G., primary, Shendage, Deepak M., additional, Wakchaure, Prasad B., additional, Phadtare, Ganesh R., additional, Bhoite, Madhavrao Y., additional, Gangopadhyay, Ashok Kumar, additional, Nagarajan, Kuppuswamy, additional, and Rupp, Richard Helmut, additional

Published
2014
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11. Asymmetric Synthesis of γ-Fluorinated α-Amino Acid Derivatives

Author

Shendage, Deepak M., Fröhlich, Roland, Bergander, Klaus, and Haufe, Günter

Abstract

Asymmetric alkylation of (S)-Boc-BMI (1a, BMI = 2-tert-butyl-3-methylimidazolidin-4-one) and its α-methyl derivative 1b with 2-fluoroallyl tosylate, subsequent mild acidic deprotection of the products 2a and 2b, and basic hydrolysis of the thus formed N-methylamides 4a and 4b gave (S)-2-amino-4-fluoropent-4-enoic acid (5a) and (S)-2-amino-4-fluoro-2-methylpent-4-enoic acid (5b). Basic hydrolysis of compound 4a was accompanied by partial racemization, which was overcome by applying a new stereoconservative deamidation procedure. The alkylated cis-configured product 2a formed under kinetic control epimerized on refluxing with 2 n NaOH to give the thermodynamically more stable trans isomer 9. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Published
2005
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12. Highly efficient stereoconservative amidation and deamidation of alpha-amino acids.

Author

Shendage DM, Fröhlich R, and Haufe G

Subjects
Models, Molecular, Stereoisomerism, Amides chemistry, Amino Acids chemistry
Abstract

[reaction: see text] An overall stereoconservative protection and deprotection method of amino and carboxyl groups is presented. N-Phthaloyl N'-alkyl secondary amides of alpha-amino acids can be generated from corresponding N-phthaloyl amino acids by coupling reaction of N-alkylamines using mixed anhydride method. These secondary amides can be transformed by thermal rearrangement of intermediate nitrosoamides to O-alkyl esters with retention of configuration and excellent yields.

Published
2004
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