33173-34-1Relevant academic research and scientific papers
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.
Claisen condensation as a facile route to an α-alkoxy-cinnamate: Synthesis of ethyl (2S)-2-ethoxy-3-(4-hydroxyphenyl)propanoate
Linderberg, Mats T.,Moge, Mikael,Sivadasan, Sivaprasad
, p. 838 - 845 (2013/09/03)
The title compound was prepared from p-anisaldehyde and ethyl ethoxyacetate via a racemic synthetic route. The synthesis involves a Claisen-type condensation in which the elimination was unexpectedly promoted by an excess of the ester. The process has been successfully performed on a 2000-L scale with a total yield over seven steps of 19%.
Chiral 2-Benzopyran-3-carboxylates by Oxa-Pictet-Spengler Reaction of (S)-3-Phenyllactic Acid Derivatives
Wuensch, Bernhard,Zott, Matthias
, p. 39 - 46 (2007/10/02)
Starting with (S)-tyrosine, the methyl (S)-3-(3,4-dihydroxyphenyl)lactate (15b) was prepared by acylation, desamination and Dakin oxidation.The phenyl moiety of 15b was sufficiently activated for the reaction with aromatic and aliphatic aldehydes and ketones to yield the alkyl (3S)-2-benzopyran-3-carboxylates 16 and 19.On the other hand, the oxa-Pictet-Spengler reaction of the aryl unsubstituted (S)-3-phenyllactic acid (6) succeeds only with aromatic aldehydes.It was shown that the enantiomeric purity of the compounds 13, 14, 15, 16 and 19 was greater than 96percent ee. Key Words: Oxa-Pictet-Spengler reaction / (S)-3-Phenyllactates / (3S)-2-Benzopyran-3-carboxylates
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.
