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3-(Dimethylamino)-2,2-dimethyl-2H-azirin als alpha-Aminoisobuttersäure (Aib)-Aquivalent: Cyclische Depsipeptide durch direkte Amid-Cyclisierung


Obrecht, Daniel; Heimgartner, Heinz (1987). 3-(Dimethylamino)-2,2-dimethyl-2H-azirin als alpha-Aminoisobuttersäure (Aib)-Aquivalent: Cyclische Depsipeptide durch direkte Amid-Cyclisierung. Helvetica Chimica Acta, 70:329-338.

Abstract

In MeCN at room temperature, 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1) and alpha-hydroxycarboxylic acids react to give diamides of type 8 (Scheme 3). Selective cleavage of the terminal N,N-dimethylcarboxamide group in MeCN/H2O leads to the corresponding carboxylic acids 13 (Scheme 4). In toluene/PhSH, phenyl thioesters of type 11 are formed (see also Scheme 5). Starting with diamides 8, the formation of morpholin-2,5-diones 10 has been achieved either by direct amide cyclization via intermediate 1,3-oxazol-5(4H)-ones 9 or via base-catalyzed cyclization of the phenyl thioesters 11 (Scheme 3). Reaction of carboxylic acids with 1, followed by selectivc amide hydrolysis, has been used for the construction of peptides from alpha-hydroxy carboxylic acids and repetitive alpha-aminoisobutyric-acid (Aib) units (Scheme 4). Cyclization of 14a, 17a, and 20a with HCI in toluene at
100° gave the 9-, 12-, and 15-membered cyclic depsipeptides 15, 18, and 21, respectively.

Abstract

In MeCN at room temperature, 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1) and alpha-hydroxycarboxylic acids react to give diamides of type 8 (Scheme 3). Selective cleavage of the terminal N,N-dimethylcarboxamide group in MeCN/H2O leads to the corresponding carboxylic acids 13 (Scheme 4). In toluene/PhSH, phenyl thioesters of type 11 are formed (see also Scheme 5). Starting with diamides 8, the formation of morpholin-2,5-diones 10 has been achieved either by direct amide cyclization via intermediate 1,3-oxazol-5(4H)-ones 9 or via base-catalyzed cyclization of the phenyl thioesters 11 (Scheme 3). Reaction of carboxylic acids with 1, followed by selectivc amide hydrolysis, has been used for the construction of peptides from alpha-hydroxy carboxylic acids and repetitive alpha-aminoisobutyric-acid (Aib) units (Scheme 4). Cyclization of 14a, 17a, and 20a with HCI in toluene at
100° gave the 9-, 12-, and 15-membered cyclic depsipeptides 15, 18, and 21, respectively.

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Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:German
Date:1987
Deposited On:21 May 2014 14:44
Last Modified:05 Apr 2016 17:52
Publisher:Wiley-Blackwell
ISSN:0018-019X
Funders:Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung, F. Hoffmann-La Roche & Co. AG, Basel, Prof. Hans-E. Schmid-Stiftung

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