89656-90-6

Upstream product

• 64-17-5 ethanol 
• 259800-73-2 2,3-O-isopropylidene-γ-D-ribonolactone (2R)-2-benzyl-2-methylacetoacetate 
• 609-14-3 2-acetylpropanoic acid ethyl ester 
• 100-39-0 benzyl bromide 
• 139616-51-6 ethyl (2RS)-3,3-<(R,R)-cycloheptane-1,2-dioxy>-2-methylbutanoate 
• 259800-72-1 2,3-O-isopropylidene-γ-D-ribonolactone 2-methylacetoacetate 
• 104372-11-4 N-<2-(ethoxycarbonyl)-1-methylprop-1-enyl>-L-valine tert-butyl ester 

Downstream Products

• 123618-23-5 ethyl (2S)-2-acetylamino-2-methyl-3-phenylpropanoate 
• 30990-90-0 (S)-α-methyl-phenylalanine hydrochloride 

Relevant academic research and scientific papers

Catalytic asymmetric alkylation of α-cyanocarboxylates and acetoacetates using a phase-transfer catalyst

The catalytic asymmetric alkylation of α-cyanocarboxylates and acetoacetates with an alkyl halide was performed under phase-transfer conditions to afford compounds which have a chiral quaternary carbon with up to 97% and 94% ee, respectively. As applicati

Asymmetric synthesis of quaternary α-amino acids using D-ribonolactone acetonide as chiral auxiliary

We describe a new simple methodology to prepare enantiopure α,α- dialkylglycines based on the use of commercially available D-ribonolactone as a chiral auxiliary. Enantiopure α-methyl and α-butyl series are prepared through diastereoselective alkylation and subsequent Schmidt rearrangement of α,α-dialkylacetoacetates of D-ribonolactone acetonide. Absolute configuration was assigned through preparation of enantiopure 4,4- disubstituted 3-methyl-2-pyrazolin-5-ones.

Application of (2R,3R)-dihydroxy-1,2,3,4-tetrahydronaphthalene to asymmetric synthesis

(2R,3R)-Dihydroxy-tetrahydronaphthalene, prepared via an efficient chemoenzymatic procedure from naphthalene, has been successfully tested, as a chiral auxiliary in diastereoselective conjugate additions of lithium dialkylcuprates to α,β-unsaturated ester

Asymmetric Alkylation Using Chiral Cyclic Diols to Prepare a Quaternary Carbon

Asymmetric alkylation of cyclic and acyclic β-keto ester acetals (4, 5, 13, 14, and 18) with C2-symmetric cycloalkane-1,2-dioxy moiety proceeded in a highly diastereoselective manner to afford enol ethers (9-12, 15-17, 19a-c) with a chiral quat

Stereoselective reactions. XXI. Asymmetric alkylation of α-alkyl β-keto esters to α,α-dialkyl β-keto esters having either (R)- Or (S)-chiral quaternary center depending on the solvent system

Asymmetric alkylation reaction of chiral enamines prepared from α-alkyl β-keto esters and (S)-valine tert-butyl ester leading to either enantiomer is described. Lithiated chiral enamines can be alkylated with alkyl halides in a toluene solvent in the presence of HMPA to give, after hydrolysis, α,α-dialkyl β-keto esters in 70-99%ee. The reactions in the presence of THF, dioxolane, or trimethylamine, instead of HMPA, afford the corresponding antipodes with enantiomeric purities of 44-92%ee. The present method provides a procedure for the synthesis of both enantiomers of α,α-dialkyl β-keto esters in high enantiomeric purities starting from the same chiral enamines.