128994-27-4

Upstream product

• 126135-38-4 Methyl (+/-)-γ-hydroxy-γ-tolylbutyrate 
• 1020690-39-4 (S)-3-(4'-methylbenzoyl)-N-(α-phenylethyl)propanamide 
• 4521-22-6 4-(4-methylphenyl)butyric acid 
• 36440-63-8 ethyl 4-(4-methylphenyl)butanoate 
• 108-88-3 toluene 
• 4619-20-9 3-(4-methylbenzoyl)propionic acid 
• 23132-33-4 5-Hydroxy-1-methyl-5-(4-methylphenyl)pyrrolidin-2-one 
• 106-38-7 para-bromotoluene 
• 89108-49-6 1-(1-azidovinyl)-4-methyl benzene 
• 57498-54-1 methyl 4-(4-methylphenyl)-4-oxobutanoate 
• 55088-80-7 1-(cyclopropylidenemethyl)-4-methylbenzene 

Relevant academic research and scientific papers

Preparation of enantioenriched γ-substituted lactones via asymmetric transfer hydrogenation of β-azidocyclopropane carboxylates using the ru-TsDPEN complex

The asymmetric transfer hydrogenation of racemic β-azidocyclopropane carboxylates has been explored. Ru-TsDPEN B is found to be a good catalyst for the formation of enantioenriched γ-lactones through a four-step sequence of azide reduction/cyclopropane ri

Biocatalytic Asymmetric Reduction of γ-Keto Esters to Access Optically Active γ-Aryl-γ-butyrolactones

An efficient stereoselective syntheses of a series of functionalized optically active γ-aryl-γ-butyrolactones is achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ-keto esters employing wild-type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog-specific NADH-dependent (S)-1-phenylethanol dehydrogenase [(S)-PED] and the anti-Prelog-specific (R)-1-(4-hydroxyphenyl)-ethanol dehydrogenase [(R)-HPED], respectively.Biotransformations catalyzed by both enzymes, followed by TFA-catalyzed cyclization of the resulting γ-hydroxy esters, furnished the respective (S)- and (R)-configured products with exquisite optical purity (up to >99% ee). The synthetic value was demonstrated on preparative scale for the asymmetric bioreduction of the model compound, methyl 4-oxo-4-phenylbutanoate, affording optically pure (S)-γ-phenyl-γ-butyrolactone (>99% ee) in 67–74% isolated yield at 89–95% conversion depending on the applied scale. (Figure presented.).

Combined Photoredox/Enzymatic C?H Benzylic Hydroxylations

Chemical transformations that install heteroatoms into C?H bonds are of significant interest because they streamline the construction of value-added small molecules. Direct C?H oxyfunctionalization, or the one step conversion of a C?H bond to a C?O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single-flask photoredox/enzymatic process for direct C?H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity. This unified strategy advances general photoredox and enzymatic catalysis synergy and enables chemoenzymatic processes for powerful and selective oxidative transformations.

Synthesis of Enantiopure γ-Lactones via a RuPHOX-Ru Catalyzed Asymmetric Hydrogenation of γ-Keto Acids

A RuPHOX?Ru catalyzed asymmetric hydrogenation of γ-keto acids has been developed, affording the corresponding enantiopure γ-lactones in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C) under the indicated reaction conditions and the resulting products can be transformed to several enantiopure building blocks, biologically active compounds and enantiopure drugs. (Figure presented.).

Preparation of optically active 4-substituted γ-lactones by lipase-catalyzed optical resolution

Optically active 4-substituted γ-lactones (3 and 4) were synthesized effectively using lipase-catalyzed optical resolution. N-methyl-4-hydroxyalkanamides (rac-1a-i) as substrates were prepared from N-methylsuccinimide. The alkylation of N-methylsuccinimid

Cascade enantioselective synthesis of γ-aryl-γ-butyrolactones with a delayed stereoselective step

Enantioselective synthesis of γ-aryl-γ-butyrolactones is achieved using (S)-1-phenylethylamine as a chiral auxiliary. The synthesis involves cascade formation-destruction-formation of the chiral centre with a delayed stereoselective step. The actual stere

Enantioselective synthesis of γ-aryl-γ-butyrolactones by sequential asymmetric epoxidation, ring expansion, and Baeyer-Villiger oxidation

(Chemical Equation Presented) This paper describes an enantioselective synthesis of γ-butyrolactones, using the N-tolyl-substituted oxazolidinone-containing ketone as catalyst and Oxone as oxidant via a sequential asymmetric epoxidation of benzylidenecyclopropanes, ring expansion, and Baeyer-Villiger oxidation. Up to 91% ee was obtained. Optically active cyclobutanones can also be obtained by suppressing the Baeyer-Villiger oxidation with use of more ketone catalyst and less Oxone.

A convenient route to optically active γ-substituted γ-lactones

Sodium borohydride reduction of 4-substituted (-)-menthyl/ (-)-bornyl-4-oxobutanoates followed by simple trituration in acidic medium at low temperature resulted in the formation of optically active γ-substituted γ-lactones.

Lipase-Catalyzed Preparation of Optically Active γ-Butyrolactones in Organic Solvents

Lipases in anhydrous organic solvents catalyze the lactonization of esters of γ-hydroxy carboxylic acids with a high degree of stereospecifity.Under these conditions the lipases exhibit both enantioselectivity and prochiral selectivity.We exploited the enzymes' enantioselectivity for synthesis of chiral lactones from racemic γ-hydroxy esters and their prochiral stereospecifity, i.e. the ability to discriminate between enantiotopic groups of a prochiral molecule, for the enantioconvergent lactonization of symmetrical γ-hydroxy diesters.This approach was used to develop a convenient, high yielding, and stereoselective route to several optically active γ-substituted γ-butyrolactones.