78044-63-0

Upstream product

• 78044-61-8 ethyl (S)-2-acetyl-5-chloro-2-methyl-4-hexenoate 
• 78044-60-7 ethyl (2S)-5-chloro-2((S)-1-hydroxyethyl)-2-methyl-4-hexenoate 
• 609-14-3 2-acetylpropanoic acid ethyl ester 
• 27372-03-8 (3S)-3-Hydroxy-2-methylbutansaeure-ethylester 
• 1012796-69-8 C₁₆H₂₄O₇ 
• 141-52-6 sodium ethanolate 
• 1012796-81-4 C₁₆H₂₄O₇ 
• 78-94-4 methyl vinyl ketone 
• 2449-05-0 dibenzyl azodicarboxylate 
• 78044-62-9 ethyl (S)-2-acetyl-2-methyl-5-oxohexanoate 
• 193468-16-5 (2Z)-(+)-ethyl 2-methyl-3-[(S)-α-methylbenzylamino]-2-butenoate 

Relevant academic research and scientific papers

Asymmetric enamine catalysis with β-ketoesters by chiral primary amine: Divergent stereocontrol modes

α-Branched ketones remain a challenging type of substrates in aminocatalysis due to their congested structures as well as the associated difficulties in controlling chemo- and stereoselectivity. In this work, we have explored asymmetric aminocatalysis with α-substituted β-ketoesters. A simple chiral primary amine catalyst was identified to enable unprecedentedly effective catalysis of β-ketoesters in α-hydrazination and Robinson annulation reaction with good yields and high enantioselectivities. Stoichiometric experiments with preformed enamine ester intermediates revealed their enamine-catalytic nature as well as the critical roles of acidic additives in facilitating catalytic turnovers and in tuning the chemo- and stereoselectivity. With the identical catalytic system, the two reactions demonstrated opposite chiral inductions in terms of the absolute configurations of the newly formed stereogenic centers. Investigations into this intriguing issue by DFT have revealed divergent stereocontrol modes. For α-hydrazination, H-bonding-directed facial attack determines the stereoselectivity, whereas a steric model is applied to the Robinson annulation where dual activations of both β-ketoester and vinyl ketone/aldehyde are involved.

Stereoselective synthesis of highly enantioenriched 3-methyl-2-cyclohexen-1-ones possessing an asymmetric quaternary carbon as C-4 or C-6: a sugar template approach

The 1,4-addition of the enolate generated from α-methylated acetoacetate incorporated at C-4 of methyl 6-deoxy-2,3-di-O-(tert-butyldimethylsilyl)-α-d-glucopyranoside to methyl vinyl ketone, followed by aldol condensation of the resulting 1,4-addition prod

Michael reaction of acyclic β-enaminoesters derived from α-alkyl-β-ketoesters and chiral α-methylbenzylamine: Stereoselective generation of quaternary carbon centres

Michael reaction of electrophilic olefins with acyclic β-enaminoester substrates derived from α-substituted β-ketoesters and (R)- or (S)-α-methylbenzylamine under neutral conditions resulted in the enantioselective formation of quaternary centres. The add

THE STEREOSELECTIVE α-ALKYLATION OF CHIRAL β-HYDROXY ESTERS AND SOME APPLICATIONS THEREOF

The stereoselectivity of the α-alkylation of chiral β-hydroxy ester is discussed.The configuration of the alkylated product was proved chemically (Scheme 2) .A one pot aldol-alkylation reaction was developed leading stereoselectively to racemic(S*,S*)-α-alkyl-β-hydroxy ester (Scheme 3,4) .Baker's yeast reduction of 2-alkyl-3-keto ester led to valuable chiral (2RS,3S)-intermediates, which were converted via the corresponding dianion to compounds with a chiral quaternary C atom (Scheme 6) .Synthetic applications of the above findings are shown in the synthesis of various chiral compounds (Scheme 8 and 9) .

ON THE STEREOSELECTIVITY OF THE α-ALKYLATION OF Β-HYDROXY ESTERS. ENANTIOSELECTIVE SYNTHESIS OF 4,4- AND 6,6-DISUBSTITUTED CYCLOHEX-2-EN-1-ONES.

Stereoselective α-alkylation of the optically active β-hydroxyester 1 gives rise to 2, which was converted to the 1,5-diketone 4.Regioselective aldolcondensation of the latter furnished (S)-5 and (S)-6 respectively, each with an e.e. of 86percent.