28030-15-1Relevant articles and documents
Oxidation of Primary Alcohols and Aldehydes to Carboxylic Acids via Hydrogen Atom Transfer
Tan, Wen-Yun,Lu, Yi,Zhao, Jing-Feng,Chen, Wen,Zhang, Hongbin
supporting information, p. 6648 - 6653 (2021/09/08)
The oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids is a fundamental reaction in organic synthesis. In this paper, we report a new chemoselective process for the oxidation of primary alcohols and aldehydes. This metal-free reaction features a new oxidant, an easy to handle procedure, high isolated yields, and good to excellent functional group tolerance even in the presence of vulnerable secondary alcohols and tert-butanesulfinamides.
Enzyme-mediated synthesis of EEHP and EMHP, useful pharmaceutical intermediates of PPAR agonists
Brenna, Elisabetta,Fuganti, Claudio,Gatti, Francesco G.,Parmeggiani, Fabio
experimental part, p. 2594 - 2599 (2010/03/30)
A new scaleable synthetic route to the title compounds has been developed. The reaction pathway is based on the α-chymotrypsin-catalysed hydrolysis of the racemic ethyl 2-ethoxy-3-(p-methoxyphenyl)propanoate or of the racemic ethyl 2-methoxy-3-(p-methoxyphenyl)propanoate to give the corresponding resolved (S)-esters with excellent ee. The acids were easily separated from the (S)-esters by a simple acid-base work-up. The overall yields of 1 and 2 were 16% and 17%, respectively.
Unstable 1,1,2-Enetriols as (Probable) Intermediates in the Decarboxylation of α,β-Diketo Acids
Dahn, Hans,Rotzler, Gerhard
, p. 3080 - 3082 (2007/10/02)
During the acid hydrolysis of (hydrated) 4-aryl-2,3-diketobutyramide 2 (aryl = phenyl, o-chlorophenyl, p-methoxyphenyl), 3-aryllactic acid (5) is formed by rapid decarboxylation of the intermediate diketo acid (3).In the decarboxylation step, a further unstable intermediate is formed.The latter manifests itself by reducing 1 mol of added iodine during the hydrolysis-decarboxylation reaction, thereby forming 3-arylpyruvic acid (6), isolated instead of 5.Thus, the oxidation of the unstable intermediate by iodine is more rapid than its ketonization.It is formulated as an 1,1,2-enetriol (4), more probably than an α-hydroxyketone.
225. Nucleofilic 1,2-Shifts of Carboxamide Groups in the Benzil-Benzilic Acid Type Rearrangement of 4-Aryl-2,3-dioxobutyramides and of Quinisantine
Gowal, Heike,Spiess, Anita,Ballenegger, Marc,Duc, Laurent,Moll, Hans,et al.
, p. 2132 - 2139 (2007/10/02)
4-Aryl-2,3-dioxobutyramide hydrates 1 undergo the benzyl-benzilic acid rearrangemet to form (substituted) benzyltartronate monoamides 2.For compound 1a (Ar = Ph), it is demonstrated by isotopic labeeling that the reaction occurs exclusively by migration of the CONH2 group.Kinetic measurements with 1a-c and with the cyclic amide quinisatine 6 show that the rearrangement of the carboxamide group procceding via an alkali-catalysed step, can reach a plateau in the kobs/-> diagram (cf. the Fig.), due to complet formation of a mono-anion, and a further increase of the rate attributable to the rearrangement of a bis-anion.Comparison suggest that rearrangement involving an amide group are slower than those involving an ester group, and for this effect (as for others), the pre-equilibrium deprotonated of the hydrate is more important than a specific migration tendency.