31771-40-1

Basic information

• Product Name: (R)-4-Amino-2-hydroxybutyric acid
• Synonyms: (2R)-4-amino-2-hydroxybutyric acid
• CAS NO: 31771-40-1
• Molecular Formula: C₄H₉NO₃
• Molecular Weight: 119
• Mol File: 31771-40-1.mol
• Article Data: 6

Chemical Properties

• Boiling Point: 361.8±27.0 °C(Predicted)
• Appearance: /
• Density: 1.312±0.06 g/cm3(Predicted)
• PKA: 3.47±0.10(Predicted)
• CAS DataBase Reference: (R)-4-Amino-2-hydroxybutyric acid(CAS DataBase Reference)
• NIST Chemistry Reference: (R)-4-Amino-2-hydroxybutyric acid(31771-40-1)
• EPA Substance Registry System: (R)-4-Amino-2-hydroxybutyric acid(31771-40-1)

Safety Data

• Hazardous Substances Data: 31771-40-1(Hazardous Substances Data)

Usage

General Description

(R)-4-Amino-2-hydroxybutyric acid, also known as L-threonine, is a naturally occurring amino acid that plays a vital role in protein synthesis and various metabolic processes in the human body. It is a key component of collagen, elastin, and enamel proteins, and is also involved in the formation of neurotransmitters and lipids. L-threonine is essential for the maintenance of proper immune function and is also crucial for the growth and repair of tissues. Additionally, it is important for the production of glycine and serine, which are necessary for the synthesis of creatine and nucleic acids. L-threonine is a valuable nutritional supplement, particularly for individuals with specific dietary restrictions or those undergoing intense physical training.

Synthetic route

(R)-2-hydroxy-4-phthalimidobutyric acid → (R)-β-hydroxy-4-aminobutyric acid (31771-40-1)

Conditions	Yield
With hydrazine hydrate In ethanol for 2h; Heating;	73%

γ-phthalimidoimino-α-hydroxybutyric acid (40732-91-0) → (R)-β-hydroxy-4-aminobutyric acid (31771-40-1)

Conditions	Yield
(i) (racemate resolution using dehydroabiethylamine), (ii) aq. HCl; Multistep reaction;

(R)-4-benzyloxycarbonylamino-2-hydroxybutanoic acid (42491-77-0) → (R)-β-hydroxy-4-aminobutyric acid (31771-40-1)

Conditions	Yield
With hydrogen; palladium on activated charcoal

4-amino-n-butyric acid (56-12-2) → (S)-4-amino-2-hydroxybutanoic acid (3938-83-8, 13477-53-7, 31771-40-1, 40371-51-5) + (R)-β-hydroxy-4-aminobutyric acid (31771-40-1)

Conditions	Yield
With wildtype taurine dioxygenase Enzymatic reaction; enantioselective reaction;	A n/a B n/a

4-amino-n-butyric acid (56-12-2) → (R)-β-hydroxy-4-aminobutyric acid (31771-40-1)

Conditions	Yield
With taurine dioxygenase F206Y mutant Enzymatic reaction; enantioselective reaction;	n/a

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) + 9-fluorenylmethyl N-succinimidyl carbonate (102774-86-7) → (2R)-4-[(9-fluorenylmethoxy)carbonylamino]-2-hydroxybutyric acid (905857-47-8)

Conditions	Yield
With sodium hydrogencarbonate In 1,2-dimethoxyethane; water at 20℃; for 0.2625h;	95.8%

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) + (R)-1-bromo-5-(3-carboxy-3-hydroxypropylamino)-2,4-dinitrobenzene (261375-47-7) → (R,R)-1,5-bis(3-carboxy-3-hydroxypropylamino)-2,4-dinitrobenzene (261375-48-8)

Conditions	Yield
With sodium carbonate In acetone for 20h; Substitution; Heating;	80.6%

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) + 3-bromo-4-nitrotoluene (40385-54-4) → (R)-2-Hydroxy-4-(5-methyl-2-nitro-phenylamino)-butyric acid (188753-45-9)

Conditions	Yield
With sodium ethanolate In ethanol; N,N-dimethyl-formamide for 16h; Heating;	56%

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) → (3R)-3-hydroxy-2-pyrrolidinone (77510-50-0)

Conditions	Yield
With hydrogenchloride In ethanol for 48h; Ambient temperature;	35%
With chloro-trimethyl-silane; (Me3Si)2SiNH; trifluoroacetic acid 1) xylene, heat, 2) THF, H2O; Yield given. Multistep reaction;

1,5-dibromo-2,4-dinitrobenzene (24239-82-5) + (R)-β-hydroxy-4-aminobutyric acid (31771-40-1) → (R)-1-bromo-5-(3-carboxy-3-hydroxypropylamino)-2,4-dinitrobenzene (261375-47-7)

Conditions	Yield
With sodium carbonate In acetone for 22h; Substitution; Heating;

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) + 4-methoxy-benzoyl chloride (100-07-2) → (R)-4-(p-methoxybenzoylamino)-2-hydroxybutyric acid (78340-49-5)

Conditions	Yield
In water

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) → (R)-3-((trimethylsilyl)oxy)pyrrolidin-2-one

Conditions	Yield
With chloro-trimethyl-silane; 1,1,1,3,3,3-hexamethyl-disilazane In o-xylene

(R)-β-hydroxy-4-aminobutyric acid (31771-40-1) → (R)-4-amino-1,2-butanediol (82267-24-1)

Conditions	Yield
With lithium borohydride; chloro-trimethyl-silane In tetrahydrofuran Inert atmosphere;

Upstream product

• 57229-74-0 (S)-2-hydroxysuccinamic acid 
• 56-12-2 4-amino-n-butyric acid 
• 40732-91-0 γ-phthalimidoimino-α-hydroxybutyric acid 
• 42491-77-0 (R)-4-benzyloxycarbonylamino-2-hydroxybutanoic acid 
• 31701-91-4 (R)-2-hydroxy-4-phthalimidobutyric acid 
• 40371-50-4 S-4-benzyloxycarbonylamino-2-hydroxybutyric acid 
• 1758-80-1 L-2,4-diaminobutyrate 

Downstream Products

• 188753-46-0 (S)-2-Hydroxy-4-(5-methyl-2-nitro-phenylamino)-butyric acid 
• 188753-45-9 (R)-2-Hydroxy-4-(5-methyl-2-nitro-phenylamino)-butyric acid 
• 261375-48-8 (R,R)-1,5-bis(3-carboxy-3-hydroxypropylamino)-2,4-dinitrobenzene 
• 207305-60-0 (S)-4-[(tert-butoxycarbonyl)amino]-2-hydroxybutanoic acid 
• 850397-64-7 4-Benzyloxycarbonylamino-2S-hydroxy butyric acid ethyl ester 
• 149137-92-8 (2S)-4-(p-nitrobenzyloxycarbonyl)-amino-2-hydroxybutyric acid 
• 1455088-71-7 (S)-4-(1-cyano-4-hydroxy-7-phenoxyisoquinoline-3-carboxamido)-2-hydroxybutanoic acid 
• 1455086-97-1 2-(S)-hydroxy-4-[(4-hydroxy-7-phenoxyisoquinoline-3-carbonyl)amino]butyric acid 
• 1221492-53-0 N,N'-bis(benzyloxycarbonyl)-2-(S)-hydroxy-4-guanidino-butyric acid 
• 48172-10-7 (+)-(2S)-4-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-2-hydroxybutanoic acid 
• 78340-49-5 (R)-4-(p-methoxybenzoylamino)-2-hydroxybutyric acid 
• 261375-47-7 (R)-1-bromo-5-(3-carboxy-3-hydroxypropylamino)-2,4-dinitrobenzene 
• 40371-50-4 S-4-benzyloxycarbonylamino-2-hydroxybutyric acid 
• 111607-75-1 (S)-hydroxy-3 phenylacetyl-1 pyrrolidinone-2 

Relevant articles and documents

α-Hydroxylation of Carboxylic Acids Catalyzed by Taurine Dioxygenase

Enzymes still have a limited application scope in synthetic organic chemistry. To expand this, different strategies exist that range from the de novo design of enzymes to the exploitation of the catalytic capabilities of known enzymes by converting different substrates; denoted as substrate promiscuity. We harnessed the synthetic potential offered by the taurine dioxygenase (TauD) from Escherichia coli (E. coli) by studying its promiscuous catalytic properties in the hydroxylation of carboxylic acid substrates. TauD showed high selectivities in the hydroxylation reaction but reduced levels of activity (26 % conversion, >96 % ee). We enhanced the enzyme substrate scope and improved the conversions for the tested substrates by introducing a point mutation at position 206 (F206Y). The conversions of the improved catalyst increased by at least 140 % compared to that of the wild-type enzyme. The number of carboxylic acids that accepted by the enzyme variant doubled from four to eight carboxylic acids.

Hydroxylations microbiologiques de pyrrolidinones-2 (note de laboratoire)

Microbial hydroxylations of various pyrrolidin-2 ones, especially N-acylated, with Beauveria sulfurescens have been carried out.The regioselectivity depends on the nature of the substituent on the nitrogen atom and the hydroxylation may occur at position 3,4 or 5 of the heterocycle.Hydroxylations at position 3 or 4 occur with low enantioselectivity.

A new synthesis of L-4-amino-2-hydroxybutyric acid. Carboxyl-assisted nitrile synthesis from primary amides

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