Photocycloaddition of 5-Methoxyoxazoles to Aldehydes and ?-Keto Esters: A Comprehensive View on Stereoselectivity, Triplet Biradical Conformations, and Synthetic Applications of Paternò–Büchi Adducts

2008 ◽  
Vol 61 (8) ◽  
pp. 573 ◽  
Author(s):  
Axel G. Griesbeck ◽  
Samir Bondock
Keyword(s):  
Carboxylic Acid ◽  
Carbonyl Compound ◽  
Carbonyl Compounds ◽  
Keto Esters ◽  
Comprehensive View ◽  
Hydroxy Carboxylic Acid

The photocycloaddition of carbonyl compounds (aldehydes and keto esters, respectively) with 5-methoxyoxazoles bearing substituents at C2 and C4 is described with respect to regio- and diastereoselectivity. In all cases the reactions proceed with excellent regioselectivity and with high to moderate (exo) diastereoselectivity independent of the nature of the excited carbonyl compound. The products can be easily ring-opened to give α-amino, β-hydroxy carboxylic acid derivatives.

Asymmetric reductinon of carbonyl compounds by yeast. II. Preparation of optically active α- and β-hydroxy carboxylic acid derivatives

1976 ◽  
Vol 29 (11) ◽  
pp. 2459 ◽  
Author(s):  
BS Deol ◽  
DD Ridley ◽  
GW Simpson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carboxylic Acid ◽  
Carbonyl Compounds ◽  
Ethyl Pyruvate ◽  
Optically Active ◽  
Phenyl Acetate ◽  
Keto Esters ◽  
Hydroxy Carboxylic Acid ◽  
Hydroxy Esters ◽  
Optically Pure

α- and β-Keto esters and amides are readily reduced by an actively fermenting mutant of Saccharomyces cerevisiae and produce optically active α- and β-hydroxy esters and amides in moderate yields. Typically, methyl 2-oxo-2-phenylacetate gave methyl (R)-(-)-2-hydroxy- 2-phenyl- acetate; 2-oxo-2-phenylacetamide gave (R)-(-)-2-hydroxy-2- phenylacetamide; ethyl benzoylacetate gave ethyl (S)-(-)-3-hydroxy-3- phenylpropionate, and ethyl 2-oxocyclohexanecarboxylate gave ethyl (1R,2S)-(+)-2-hydroxycyclohexanecarboxylate. In each case, the product obtained was optically pure. However, the reduction of ethyl pyruvate to ethyl lactate produced partially racemized products.

Copper-Catalyzed Oxidative Self-Coupling of α-Amino Carbonyl Compounds for the Synthesis of Tetrasubstituted 1,4-Enediones

Synlett ◽  
2018 ◽  
Vol 29 (18) ◽  
pp. 2422-2426
Author(s):  
Bing Yi ◽  
Jiannan Xiang ◽  
Niannian Yi ◽  
Yi Xiong ◽  
Qingjun Huang ◽  
...  
Keyword(s):  
Double Bond ◽  
Carbonyl Compound ◽  
Carbonyl Compounds ◽  
Simultaneous Formation ◽  
High Stereoselectivity

A protocol for the copper-catalyzed oxidative self-coupling of α-amino carbonyl compounds has been developed for the synthesis of tetrasubstituted 1,4-enediones (Z-isomers) in moderate to good yields through the cleavage of four sp3C–H bonds and the simultaneous formation of one C=C double bond in the α-amino carbonyl compound. The strategy has the advantages of using readily available starting ­materials and of high stereoselectivity.

scholarly journals 3-Arylaziridine-2-carboxylic Acid Derivatives and (3-Arylaziridin-2-yl)ketones: The Aziridination Approaches

2021 ◽  
Vol 22 (18) ◽  
pp. 9861
Author(s):  
Boriss Strumfs ◽  
Romans Uljanovs ◽  
Kirils Velikijs ◽  
Peteris Trapencieris ◽  
Ilze Strumfa
Keyword(s):  
Carboxylic Acid ◽  
Carbonyl Compounds ◽  
Synthetic Chemistry ◽  
Significant Progress ◽  
Current Review ◽  
Recent Advances ◽  
Year 2000

Aziridination reactions represent a powerful tool in aziridine synthesis. Significant progress has been achieved in this field in the last decades, whereas highly functionalized aziridines including 3-arylated aziridine-2-carbonyl compounds play an important role in both medical and synthetic chemistry. For the reasons listed, in the current review we have focused on the ways to obtain 3-arylated aziridines and on the recent advances (mainly since the year 2000) in the methodology of the synthesis of these compounds via aziridination.

Simultaneous “O–Alkyl” and “O–Acyl” Lactone Cleavages from Hydroxy–Carboxylic Acid Initiators: Direct Access to Multiblock Architectures

2019 ◽  
Vol 52 (17) ◽  
pp. 6382-6392 ◽  
Author(s):  
Bryan Raeskinet ◽  
Sébastien Moins ◽  
Luke Harvey ◽  
Julien De Winter ◽  
Céline Henoumont ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Direct Access ◽  
Hydroxy Carboxylic Acid
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