3227-17-6

Usage

Chemical Properties

white fine crystalline powder

InChI:InChI=1/C5H9NO4/c1-5(6,4(9)10)2-3(7)8/h2,6H2,1H3,(H,7,8)(H,9,10)/p-1/t5-/m0/s1

Upstream product

• 6892-05-3 (2S)-N-acetyl-3-(3',4'-diacetoxyphenyl)-2-methylalanine 
• 89656-87-1 ethyl methyl (S)-2-acetyl-2-methylsuccinate 
• 103825-52-1 2-<(2R,4S)-3-Benzoyl-2-(tert-butyl)-1,4-dimethyl-5-oxoimidazolidin-4-yl>essigsaeure 
• 193945-94-7 (1R,3'S)-N-[3'-²Δ-(3'methyl)pyrazoline]carbonyl-2,10-camphorsultam 
• 2792-66-7 α-methyl-DL-aspartic acid 
• 1266681-10-0 methyl 2-[(3S,5aR,6aS,7aS)-2,3,5,5a,6,6a,7,7a-octahydro-3,6,6,7a-tetramethyl-2-oxobicyclo[4.1.0]hept-1⁽⁶⁾eno[3,4-b][1,4]oxazin-3-yl]acetate 
• 250264-91-6 MeO₂C-(cyclo-p-ClC₆H₄CH)-MeAsn-OMe 
• 213619-66-0 (3S,6R)-N-1-(tert-butoxycarbonyl)-3-(ethoxycarbonyl)methyl-6-isopropyl-3-methyl-5-phenyl-1,2,3,6-tetrahydro-2-pyrazinone 
• 211686-55-4 (2S,4S)-3-Benzoyl-2-isopropyl-6-methoxy-4-methyl-2,3,4,5-tetrahydro-pyrimidine-4-carboxylic acid methyl ester 

Relevant academic research and scientific papers

On the synthesis of (S)-α-methylaspartic acid by diastereoselective alkylation of a chiral 2-cyanopropanoate

A novel and efficient procedure for the synthesis of optically pure α-methylaspartic acid, based on the diastereoselective alkylation of (1S,2R,4R)-10-(dicyclohexylsulfamoyl)isobornyl 2-cyanopropanoate with α-halocarbonyl compounds, is described.

Asymmetric synthesis of α-methyl-α-amino acids via diastereoselective alkylation of (1s)-(+)-3-carene derived tricyclic iminolactone

A novel carene-based alanine-equivalent tricyclic iminolactone 16 has been synthesized via stereoselective dihydroxylation of the double bond, IBX oxidation of the secondary alcohol, esterification of the tertiary alcohol, deprotection of the resulting ester, and subsequent cyclization from commercially available (1S)-(+)-3-carene in 79% overall yield. The iminolactone 16 demonstrated high reactivity toward alkylation with a wide range of electrophiles at room temperature under phasetransfer catalysis conditions. The alkylated products were produced with excellent diastereoselectivities (>98% de) in good isolated yields (86-94%). High yields (83-91%) of optically pure (S)-R-methyl-R-substituted-R-amino acids were obtained by basic hydrolysis of the dialkylated iminolactones with the recovery of the chiral auxiliary 15 (78-87%).

Asymmetric synthesis of α-Methyl α-Amino Acids through diastereoselective alkylation under mild reaction conditions of an iminic alanine template with a 1,2,3,6-Tetrahydro-2-Pyrazinone structure

(6R)-6-Isopropyl-3-methyl-5-phenyl-1,2,3,6-tetrahydro-2-pyrazinone, obtained from (R)-valine and (S)-alanine, is highly diastereoselectively alkylated at room temperature by: a) activated alkyl halides under solid-liquid PTC conditions, b) non-activated alkyl halides with organic bases, c) electrophilic olefins employing both solid-liquid PTC conditions and organic bases, and d) allylic carbonates by means of palladium catalysis under neutral conditions. Enantiomerically pure (S)-α-methyl α-amino acids 8 are obtained by hydrolysis of the alkylated pyrazinones.

Efficient enantioselective synthesis of C(α)-methyl aspartic acid and 3-amino-3-methylpyrrolidin-2-one

The asymmetric dipolar cycloaddition reaction of Me3SiCHN2 and auxiliary-bound methacrylate affords ready entry into optically active substituted pyrazolines. Herein we disclose an unusual alkaline fragmentation reaction of optically

Enantiomerically pure tetrahydropyrimidinones in asymmetric synthesis: Preparation of a protected α-methylasparagine derivative and corresponding dipeptides

Methyl ester 5a, available in enantiomerically pure form from the amino acid asparagine via a one-pot cyclization/protection sequence, followed by esterification, can be effectively deprotonated with LDA/DMPU/LiCl. Treatment with MeI affords the corresponding alkylated adduct in enantiomerically pure form, from which α-methylaspartic acid is obtained. Variation of the amine protection group allows for the isolation of a protected carboxylic acid/free amine derivative of α-methylasparagine. The utility of H-MeAsn-OMe is demonstrated in the formation of dipeptides.

Chiral 3,6-dihydro-2H-1,4-oxazin-2-ones as alanine equivalents for the asymmetric synthesis of α-methyl α-amino acids (AMAAs) under mild reaction conditions

3,6-Dihydro-2H-1,4-oxazin-2-ones 1 act as very reactive chiral cyclic alanine equivalents and can be diastereoselectively alkylated or allylated using mild reaction conditions: potassium carbonate under phase-transfer catalysis (PTC) conditions when using activated alkyl halides, organic bases such as tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2- diazaphosphorine (BEMP) or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) when using unactivated alkyl halides, and neutral Pd(0)-catalysis when allylic carbonates are used. In most cases, the diastereoselectivity under all these different reaction conditions is excellent although the reactions are always carried out at room temperature. Hydrolysis of the obtained alkylated or allylated oxazinones allows the preparation of enantiomerically enriched (S)- α-methyl α-amino acids (S)-AMAAs. The PTC and organic base methodologies have also been applied to the synthesis of (R)-α-methyl α-amino acids starting from (R)-alanine. When dihalides are used as electrophiles under PTC or BEMP conditions, a spontaneous N-alkylation also takes place giving bicyclic oxazinones, which can be hydrolyzed to enantiomerically pure cyclic (S)-AMAAs.

New chiral alanine template with a 1,2,3,6-tetrahydro-2-pyrazinone structure for the asymmetric synthesis of α-methyl α-amino acids

(R)-6-Isopropyl-5-phenyl- 1,2,3,6-tetrahydro-2-pyrazinone, prepared from (R)-valine and (S)-alanine, reacts With activated alkyl halides and electrophilic olefins under solid-liquid PTC conditions: with K2CO3 as base, at room temperature and with high diastereoselectivity (>94%). The palladium-catalyzed allylation reaction of this alanine derivative under neutral conditions at room temperature also takes place with a de>96%. Final hydrolysis of alkylated pyrazinones affords enantiomerically pure α-methyl α-amino acids.

α-Alkylation of (S)-Asparagine with Self-Regeneration of the Stereogenic Center: Enantioselective Synthesis of α-Substituted Aspartic Acids

A convenient method for the α-alkylation of (S)-asparagine with "self-regeneration of the stereogenic center" is described. The synthetic protocol involves stereoselective conversion of (S)-asparagine into enantiopure imino ether (2S,6S)-9, which is then

Asymmetric synthesis of α-methyl α-amino acids by diastereoselective alkylation of optically active 6-isopropyl-3-methyl-2,3-dihydro-6H-1,4-oxazin-2-ones

At room temperature already highly diastereoselective alkylation of the new, cyclic, chiral alanine ester derivatives (6R)-1 can be achieved with either K2CO3 as base under solid liquid phase-transfer catalysis or Pd catalysis under neutral conditions. The products (3S,6R)-2 can be easily hydrolyzed to form (S)-α-methyl α-amino acids.

A Novel Synthesis of (R)- and (S)-α-Alkylated Aspartic and Glutamic Acids: α-Alkylated Aspartic Succinimides as New Type of β-Turn Type II and II' Mimetics

A novel and efficient synthesis of optically pure (R)- and (S)-α-methyl glutamic acid (1), (R)-and (S)-α-methyl aspartic acid (2a) and (R)- and (S)-α-isobutyl aspartic acid (2b) using L-phenylalanine cyclohexylamide 4 as chiral auxiliary is described.Crystal structures show that the (R)- and (S)-α-methyl glutamic acid derivatives (S,S)-5 and (R,S)-6 adopt β-turn type I geometries, whereas the corresponding aspartimide derivatives (R,S)-12a,b form a β-turn type II and (S,S)-11a a β-turn type II'.These findings suggest, that the succinimide derivatives of (R)- and (S)-α-alkyl aspartic acids can serve as building blocks to stabilise β-turns of type II (or II') in peptides depending on their absolute configuration.