Citramalic acid, (+)- - ≥95% , CAS No.6236-09-5

CAS: 6236-09-5 Cat. No.: C1068612 분자식: C₅H₈O₅ 분자량: 148.110 EC 번호: 228-350-1

GRADE & PURITY ≥95%

Storage

Room temperature

Specifications

사양 및 순도

≥95%

보관 조건

Room temperature

순수함

≥95%

이름과 식별자

정식 스마일

C[C@](CC(=O)O)(C(=O)O)O

IUPAC Name

(2S)-2-hydroxy-2-methylbutanedioic acid

InChIKey

XFTRTWQBIOMVPK-YFKPBYRVSA-N

INCHI

1S/C5H8O5/c1-5(10,4(8)9)2-3(6)7/h10H,2H2,1H3,(H,6,7)(H,8,9)/t5-/m0/s1

분자량

148.110

화학 및 물리적 특성

• 분자량: 148.110 g/mol
• XLogP3: -0.900
• Hydrogen Bond Donor Count: 3
• Hydrogen Bond Acceptor Count: 5
• Rotatable Bond Count: 3
• Exact Mass: 148.037 Da
• Monoisotopic Mass: 148.037 Da
• Topological Polar Surface Area: 94.800 Ų
• Heavy Atom Count: 10
• Formal Charge: 0
• Complexity: 163.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 1
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

Not applicable.

• No tested immunoassay or imaging applications (WB, IHC, IF, FC) are associated with this small-molecule reagent in the Product Data. For use in biochemical or synthetic workflows, refer to the Reaction & Applications and Reaction Conditions sections.

Biological Roles

General biological context (literature; not a claim about this specific item’s use in humans/animals)

• Metabolic pathway: Citramalate is an intermediate in the citramalate pathway for isoleucine biosynthesis found in many archaea and some bacteria, where citramalate synthase condenses acetyl-CoA and pyruvate to form citramalate, which is further processed to 2-oxobutanoate.
• Stereochemistry and enzymes: Enzymes in this pathway are stereospecific; the configuration at C2/C3 dictates substrate compatibility. When designing enzymatic assays, match the enantiomer/diastereomer to the enzyme’s preference.
• Chemical properties relevant to biology: As a dicarboxylate with a secondary alcohol, citramalate chelates certain metal ions weakly and participates in hydrogen-bond networks, influencing transport and detection in metabolomics.
• Analytical detection: Typically monitored by LC–MS/MS or GC–MS after derivatization (e.g., silylation of OH/COOH) in metabolomics workflows.

Scope of use

• This product is for research use only. No medical, diagnostic, or clinical applications are implied or supported. For biochemical assays, verify salt form, counterions, and stereochemical purity on the CoA to ensure compatibility with your system.

Buffer Applications

Applicability

• Citramalic acid is not a standard biological buffer. However, as a diprotic acid it can, in principle, contribute buffering capacity near its carboxyl pKa values.

Guidance (literature-based; not item-specific specifications)

• Expected pKa values: Hydroxy dicarboxylic acids typically display two acidic pKa values in the ~2–6 range. Exact pKa values for citramalic acid depend on stereochemistry and ionic strength; consult primary literature if precise buffering is required.
• Practical considerations: Buffer capacity will be modest and highly pH-dependent. Ionic strength and metal ions can influence activity coefficients and apparent pKa.
• Recipe hints: Prepare a stock solution in water, then titrate with NaOH/KOH to the desired pH, monitoring temperature (pKa is temperature-dependent). Filter sterilize if using in biochemical assays.

When to use alternatives

• For robust buffering between pH 2–7, established systems (acetate, citrate, MES, MOPS, phosphate) offer well-characterized pKa, low UV absorbance, and better documentation. Choose these unless citramalate is specifically required (e.g., enzyme specificity studies).

Green Alternatives

Context

• Citramalic acid is a bio-based platform molecule in certain microbial pathways and can be produced by fermentation, offering a potentially renewable alternative to petrochemical feedstocks (literature context). As a solid reagent, “green alternatives” considerations focus on sourcing and process conditions rather than replacing it as a solvent.

Greener sourcing and processing options (general guidance)

• Bio-based sourcing: Prefer suppliers documenting biotechnological production or renewable-carbon content where sustainability is mandated.
• Solvent selection: Use water or green alcohols (ethanol) for dissolution and transformations (e.g., Fischer esterification in EtOH) when compatible with your synthesis.
• Coupling chemistry: Favor carbodiimide chemistry with catalytic DMAP in greener solvents (EtOAc, 2-MeTHF) or aqueous EDC/NHS systems to avoid chlorinated solvents.
• Energy efficiency: Perform reactions at ambient temperature/pressure where feasible; use catalytic rather than stoichiometric dehydrating agents.

Comparison (illustrative; literature-based)

• Water/EtOH media vs. DMF/DMSO: Lower toxicity and easier workup/disposal; may require longer reaction times or catalysts.
• EDC·HCl (aqueous) vs. DCC (organic): Reduced allergenic sensitization risk; urea byproducts are more manageable in water.

Trade-offs

• Greener media may reduce solubility/reactivity for some steps; consider temporary derivatization (e.g., ester formation) to operate in benign solvents, then deprotect under mild conditions.

Pharmaceutical Uses

Scope

• No pharmacopeial grade or excipient status is provided for this item. This product is for research use only.

General formulation context (literature/industry practice)

• Role as an acidulant/chelating co-former: Dicarboxylic acids and hydroxy acids are sometimes used as acidulants, counterions, or co-crystal formers to modify API solubility or stability. If considering citramalic acid analogously, verify toxicological acceptability and regulatory status early.
• Salt/cocrystal screening: The two carboxyl groups allow formation of diverse salts with amines and metals; the secondary alcohol can participate in hydrogen bonding, impacting crystal packing.
• Process considerations: High polarity favors aqueous processing; residual solvent control and water content (KF) should be defined if used in any GMP-adjacent research.

Compliance reminder

• Do not use in human or veterinary products without appropriate qualification and regulatory clearance. No therapeutic claims are made or implied.

Physical Properties

Item-specific data (from Product Data)

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.

Literature/general properties (for reference only; not item-specific specifications)

• Physical state: Typically a crystalline solid (literature, dicarboxylic hydroxy acids).
• Molecular formula: C5H8O5 (literature)
• Formula weight: ~148.11 g/mol (literature)
• Acid–base: Diprotic acid with one secondary alcohol; expected two carboxyl pKa values in the acidic range (roughly 2–6, literature for related hydroxy dicarboxylic acids). Exact pKa values depend on stereochemistry and ionic strength.
• Solubility: High water solubility expected; also soluble in polar protic solvents (MeOH, EtOH) and polar aprotic solvents when ionized or as esters/salts (literature, analogous to malic acid behavior).
• LogP: Expected negative/low due to multiple polar groups (literature trend for hydroxy dicarboxylic acids).
• Melting behavior: Many hydroxy-dicarboxylic acids show melting/decomposition upon heating; exact temperature varies with isomer and hydration (literature).
• Hygroscopicity: Such acids may absorb moisture under high humidity; confirm for this item on the CoA.

Notes

• Do not treat literature values as specifications. For exact numerical properties of this SKU (mp, water content, metal limits, RI, density, UV cutoff, etc.), consult the item’s CoA/Spec Sheet.

Quality and Grades

Item-specific quality information (from Product Data)

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/antioxidants: Not specified for this item; refer to CoA/Spec Sheet.

Interpretation and guidance (general)

• Without a declared grade, end-users should verify suitability for purpose via the CoA, focusing on:
  • Assay/purity method (e.g., qNMR, titration, HPLC).
  • Identity verification (NMR, IR, MS, optical rotation for the “(+)” enantiomer).
  • Chiral purity (enantiomeric excess) and diastereomeric ratio, since citramalic acid bears two stereocenters; verify by chiral HPLC or derivatization methods.
  • Residual solvents, water content (Karl Fischer), and inorganic residues (sulfated ash or metals, if applicable).
  • Bioburden/endotoxin only if your workflow requires it (e.g., biochemical assays); this is not implied unless specified.
• If HPLC- or LC-MS-grade materials are required (e.g., for metabolomics), ensure low UV background and volatile impurity limits are documented; otherwise, standard reagent grades may be adequate for synthesis and biochemistry work.

Documentation

• Rely on the item’s CoA/Spec Sheet for acceptance criteria, test methods, and batch-specific results. Do not extrapolate from literature or other vendors’ specs.

Reaction and Applications

Research and manufacturing contexts where (+)-citramalic acid is useful (general; expand based on your workflow)

• Chiral building block: With two stereocenters (C2–C3), citramalic acid provides access to stereodefined 1,2-diols, 2-hydroxy acids, and derivatives after selective protection/reduction. Optical activity (“(+)”) enables enantioinduction or resolution strategies when converted to derivatives.
• Esterification and protection chemistry: Readily forms mono- and diesters (Fischer conditions; DCC/EDC coupling), enabling solubility tuning and orthogonal protection of the two carboxyl groups for stepwise transformations.
• Lactonization/dehydration: Under acidic or dehydrating conditions, hydroxy dicarboxylic acids can cyclize to lactones or dehydrate to unsaturated acids/anhydrides. Control temperature and acid strength to minimize over-dehydration or racemization.
• Redox transformations: The secondary alcohol can be oxidized (e.g., TEMPO/bleach, Dess–Martin) to a keto-dicarboxylic acid; conversely, carboxyl reduction (BH3·THF, LiAlH4) affords diols/triols—use protecting groups to maintain selectivity.
• Salt formation/phase behavior: Alkali or ammonium salts enhance water solubility and are useful for biochemical assays or as phase-transferable substrates.
• Biocatalysis: Substrate or product in enzymatic routes related to the citramalate pathway (e.g., citramalate synthase assays); ensure stereochemistry matches enzyme specificity.

Practical tips

• Drying: If water-sensitive chemistry is planned (e.g., carbodiimide couplings), dry under high vacuum at ambient or mild heat. Avoid overheating to prevent dehydration.
• Racemization control: Conduct reactions at the lowest effective temperature and shortest time under acidic/basic conditions to preserve stereochemical integrity; use mild coupling reagents and neutral conditions when possible.

Reaction Conditions

General conditions (literature guidance; adjust to your system)

• Fischer esterification: ROH (MeOH/EtOH, 5–20 equiv) with catalytic H2SO4 or p-TsOH (1–5 mol%), reflux 2–24 h; remove water (Dean–Stark for higher alcohols) to drive to completion. Monitor for dehydration/racemization at elevated temperature.
• Steglich esterification: DCC (1.1–1.5 equiv), DMAP (0.1 equiv) in DCM/DMF (0–25 °C, 2–18 h). Filter dicyclohexylurea; minimal epimerization under mild conditions.
• Amide coupling: EDC·HCl (1.2–1.5 equiv) with HOBt or HOAt additives in DMF or aqueous-organic media (pH ~5.5) at 0–25 °C for 2–16 h; monitor by LC. HATU/DIPEA in DMF affords higher reactivity but increases risk of epimerization.
• Alcohol oxidation: TEMPO/NaOCl (pH 8–9, 0–5 °C) or Dess–Martin periodinane in DCM (0–25 °C) to minimize over-oxidation of sensitive motifs.
• Reduction: BH3·THF (1–3 equiv per CO2H) at 0–25 °C; quench carefully. LiAlH4 will reduce carboxyls and may affect the secondary alcohol; protect if needed.
• Lactonization/dehydration: p-TsOH or methanesulfonic acid in toluene/benzene with azeotropic water removal at 80–110 °C; monitor to avoid over-dehydration and loss of stereochemical integrity.

Yields and selectivity

• Expected yields vary with protection strategy and stereochemical stability; 60–90% is typical for well-optimized esterifications/couplings (literature ranges). Always confirm by NMR and chiral HPLC when stereochemistry matters.

Safety and Handling

Item-specific safety (from Product Data)

• GHS classification: Not specified for this item; refer to SDS.
• Signal word / H-statements / Pictograms: Not specified for this item; refer to SDS.
• Storage conditions: Room temperature (per Product Data).

General safety guidance (literature/standard practice; defer to SDS)

• Likely hazards: Organic dicarboxylic acids are generally of low acute toxicity but are irritants to eyes, skin, and mucous membranes. Dust may cause respiratory irritation.
• Personal protective equipment (PPE): Laboratory coat, safety glasses or goggles, and appropriate chemical-resistant gloves (e.g., nitrile). Use dust control (weighing in fume hood) to minimize inhalation.
• Handling: Avoid creating dust; do not breathe dust. Prevent contact with bases and reactive carbonyl-activating agents unless intended for reaction. Wash thoroughly after handling.
• Incompatibilities: Strong bases (will neutralize); strong oxidizers (may cause exotherm on mixing); dehydrating agents (e.g., SOCl2, P2O5) can drive esterification/dehydration; avoid unintended contact. Metals are generally compatible, but avoid contact with reactive metals in acidic conditions due to possible hydrogen evolution.
• First aid (overview):
  • Eye/skin contact: Rinse with water for at least 15 minutes; remove contaminated clothing. Seek medical attention if irritation persists.
  • Inhalation: Move to fresh air; seek medical attention if symptoms continue.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical advice.
• Fire: Substance itself is not highly flammable but is organic; in fire may produce CO/CO2. Use water spray, CO2, dry chemical, or foam. Firefighters should wear SCBA.

Always consult the product SDS for authoritative hazard classification and response procedures.

Solvent Selection

Applicability

• Citramalic acid is a polar, polyfunctional solid reagent, not a solvent. Solvent selection pertains to dissolving/processing it in reactions or analyses.

General solvent guidance (literature/experience)

• Aqueous systems: Freely soluble in water in its acid or salt forms; buffer or pH-adjust to improve dissolution or control reactivity.
• Alcohols: Methanol and ethanol typically dissolve citramalic acid well; useful for Fischer esterification (acid catalysis) or stock solutions for biochemical assays.
• Polar aprotic: DMF, DMSO, and NMP can dissolve the neutral acid; DMSO/H2O mixtures are effective for biological assays but consider downstream compatibility.
• Nonpolar solvents: Poorly soluble in hydrocarbons/ethers; convert to esters or salts to enhance solubility in organic phases.

Selection tips

• For esterification: Use anhydrous ROH with catalytic H2SO4 or p-TsOH, or activate carboxyls (DCC/EDC in DMF/DCM) to limit water.
• For crystallization/purification: Water/EtOH or water/acetone mixtures can exploit differential solubility between acid and esters/salts.
• For LC methods: Aqueous mobile phases with formic acid or ammonium formate buffers are typical; ensure full dissolution and filtration.

Comparison (contextual)

• Versus malic acid: Slightly more hydrophobic due to a methyl substituent; may exhibit lower aqueous solubility and altered pKa values, impacting buffer range and chromatographic retention.

Storage and Reconstitution

Item-specific guidance (from Product Data)

• Storage conditions: Room temperature.
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.

General best practices (supplementary; not item-specific specifications)

• Container: Store tightly closed in a clean, dry container to minimize moisture uptake and contamination. Consider desiccation if performing moisture-sensitive chemistry.
• Light/heat: Protect from excessive heat. Avoid prolonged exposure to >40 °C to prevent dehydration or racemization.
• Stability: Hydroxy dicarboxylic acids are generally stable at ambient conditions. For long-term storage or if ultra-trace purity is critical, consider cool, dry conditions.

Reconstitution and solution handling

• Solubility: Readily dissolves in water to form clear solutions; adjust pH with NaOH/KOH to prepare citramalate salts if needed. Also soluble in MeOH/EtOH and DMSO.
• Preparation: For analytical or biochemical use, prepare fresh solutions, filter (0.2 µm), and record pH/ionic strength. Avoid strong acidic or basic conditions if stereochemical integrity must be preserved.
• Freeze–thaw: If storing aqueous solutions, aliquot and freeze to avoid repeated freeze–thaw cycles; verify stability at your storage temperature.

Always refer to the CoA/Spec Sheet and SDS for batch-specific instructions and safety information.

Structure and Identity

Item-specific identifiers (from Product Data)

• SKU: C1068612
• Product name: Citramalic acid, (+)-
• CAS: 6236-09-5
• InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.

Literature/Computed identity (for reference only; not item-specific specifications)

• Common name(s): Citramalic acid; 2-methylmalic acid; 2-methyl-2-hydroxybutanedioic acid (generic)
• Molecular formula (literature): C5H8O5
• Molecular weight (literature): ~148.11 g/mol
• Stereochemistry: “(+)” indicates an optically active enantiomer. Citramalic acid possesses two adjacent stereogenic centers (at C2 bearing CH3 and at C3 bearing OH), giving two diastereomeric pairs of enantiomers; “(+)” designates the handedness by optical rotation rather than absolute configuration unless otherwise specified on the CoA.

Structural features (general description)

• Functional groups: Two carboxylic acids (dicarboxylic), one secondary alcohol.
• Backbone: A three-carbon chain bearing terminal and internal carboxyl groups, with a methyl substituent at C2 and a hydroxyl group at C3.
• 2D structural description (words): HOOC–CH(CH3)–CH(OH)–COOH. The molecule is polar and capable of intramolecular H-bonding; multiple hydrogen-bond donors/acceptors support strong intermolecular associations in the solid state.

Notes

• Where exact stereochemical descriptors (e.g., (2R,3S)) are required, consult the Certificate of Analysis (CoA) for this catalog item.

Synthetic Utility

Functional group leverage (general)

• Carboxyl groups: Enable amide coupling (EDC/HOBt, HATU), esterification (Fischer, Steglich), anhydride formation, decarboxylation under forcing conditions, and salt formation for phase behavior control.
• Secondary alcohol: Amenable to oxidation (PCC, TEMPO, Dess–Martin) to a ketone, activation (mesylate/tosylate) for substitution/elimination, or protection (silyl ethers, acylation) to enable orthogonal chemistry.
• Stereocenters: Provide access to enantioenriched scaffolds; careful conditions can preserve or relay stereochemistry into downstream products (e.g., anti/syn 1,2-diol derivatives).

Typical transformations (examples; literature-based)

• Stepwise protection of diacid as mixed esters, enabling selective amidation at one position.
• Intramolecular cyclization to lactones under acidic dehydrating conditions; subsequent ring-opening yields differentiated hydroxyacids.
• Borane-mediated reduction of carboxyls to primary alcohols while retaining stereochemistry at the secondary alcohol center under mild conditions.
• Formation of citramalate salts for use in phase-transfer or as chiral auxiliaries after derivatization.

Retrosynthetic value

• Serves as a chiral pool starting material toward 2-methyl-1,2-diols, 2-methyl-3-hydroxy acid derivatives, and substituted succinate analogs. Diastereocontrol can be exerted by substrate-controlled reactions leveraging the pre-existing stereocenters.

Target Specificity

Not applicable.

• This product is a small-molecule reagent, not a biological targeting reagent or antibody. No antigen/epitope/clone/isotype information applies.

자주 묻는 질문

How should this product be stored?

Store at room temperature.