4-Methyl-5,6-dihydro-2H-pyran-2-one: Properties & Applications
4-Methyl-5,6-dihydro-2H-pyran-2-one: Properties & Applications
4-Methyl-5,6-dihydro-2H-pyran-2-one is an unsaturated six-membered lactone bearing a 4-methyl substituent and an endocyclic double bond, making it a valuable building block in organic synthesis and medicinal chemistry research.
- Chemical Name
- 4-Methyl-5,6-dihydro-2H-pyran-2-one
- Core Structure
- Six-membered unsaturated lactone (alpha,beta-unsaturated delta-lactone)
- SKU
- A1062456
- Key Functional Groups
- Lactone carbonyl (C=O), endocyclic C=C double bond, methyl substituent at C-4
- Reactivity Class
- Michael acceptor; susceptible to nucleophilic addition, Diels-Alder cycloaddition, and ring-opening reactions
- Supplier
- Aladdin Scientific (SKU: A1062456)
Chemical Structure and Properties
4-Methyl-5,6-dihydro-2H-pyran-2-one belongs to the family of dihydropyranones, specifically classified as an alpha,beta-unsaturated delta-lactone. Its six-membered ring contains one oxygen atom, a lactone carbonyl group, and an endocyclic double bond between C-3 and C-4, with a methyl group at the C-4 position. This arrangement confers significant electrophilic character at the beta-carbon (C-3), making the compound an effective Michael acceptor.
The combination of the electron-withdrawing lactone carbonyl and the conjugated alkene renders the molecule reactive toward a broad spectrum of nucleophiles, including amines, thiols, and stabilized carbanions. The six-membered ring geometry provides moderate conformational rigidity compared to smaller lactone rings, influencing both its reactivity profile and its interactions with biological targets.
As with other alpha,beta-unsaturated lactones, the compound should be handled with appropriate precautions; unsaturated lactones may act as electrophilic alkylating agents. Refer to the Safety Data Sheet (SDS) before use.
Synthesis and Role as a Building Block
Unsaturated delta-lactones such as 4-Methyl-5,6-dihydro-2H-pyran-2-one are widely employed as versatile intermediates in the synthesis of complex natural products and pharmaceutical candidates. The endocyclic double bond can participate in Diels-Alder cycloadditions, either as a dienophile or as part of a diene system in suitably activated derivatives, enabling rapid construction of polycyclic frameworks.
The lactone ring itself is amenable to selective reduction, ring-opening with nucleophiles, or further functionalization at the alpha and beta positions, providing multiple handles for diversification. The C-4 methyl group introduces a stereogenic center upon further functionalization, making this scaffold relevant to enantioselective synthesis strategies.
Researchers working on the total synthesis of terpenoid lactones, polyketide natural products, or bioactive heterocyclic targets may find 4-Methyl-5,6-dihydro-2H-pyran-2-one a convenient and efficient starting material or intermediate.
Laboratory Handling and Storage Recommendations
As an alpha,beta-unsaturated lactone, 4-Methyl-5,6-dihydro-2H-pyran-2-one should be handled in a well-ventilated fume hood. Personal protective equipment including chemical-resistant gloves, laboratory coat, and safety glasses should be worn at all times during handling. Avoid inhalation of vapors and contact with skin or eyes.
The compound should be stored in a tightly sealed container, away from heat, ignition sources, and incompatible materials such as strong bases, strong oxidizers, and reducing agents. Cool, dry storage conditions are recommended to maintain reagent integrity over time. Consult the product SDS provided by Aladdin Scientific for full hazard information and disposal guidance.
Upon receipt, it is advisable to inspect the reagent for appearance and to record the lot number for traceability. For long-term storage stability, refer to the certificate of analysis (CoA) supplied with each lot.
Applications in Medicinal and Synthetic Chemistry
Dihydropyranone scaffolds are recurrent structural motifs in biologically active natural products and drug candidates. The alpha,beta-unsaturated lactone moiety is associated with a range of biological activities, including antimicrobial, anti-inflammatory, and cytotoxic properties, primarily attributed to the electrophilic reactivity of the Michael acceptor system.
In synthetic chemistry, 4-Methyl-5,6-dihydro-2H-pyran-2-one serves as a platform for the preparation of more complex heterocyclic or carbocyclic structures via cycloaddition or annulation strategies. Its use as a dienophile in asymmetric Diels-Alder reactions has been explored for the construction of enantioenriched cyclohexene-fused lactones relevant to natural product synthesis.
Researchers in fragment-based drug discovery may also utilize this compound as a fragment or fragment-like scaffold to probe biological targets, leveraging the warhead reactivity of the enone-lactone system for covalent fragment screening approaches.
Frequently asked questions
What type of reactivity does 4-Methyl-5,6-dihydro-2H-pyran-2-one exhibit?
4-Methyl-5,6-dihydro-2H-pyran-2-one is an alpha,beta-unsaturated lactone that functions as a Michael acceptor. It readily undergoes 1,4-conjugate addition with nucleophiles such as amines, thiols, and stabilized carbanions, and can also participate in Diels-Alder cycloadditions as a dienophile.
How should 4-Methyl-5,6-dihydro-2H-pyran-2-one be stored to maintain reagent quality?
The compound should be stored in a tightly sealed container under cool, dry conditions, away from heat sources, light, strong oxidizers, and strong bases. Always consult the Aladdin Scientific Certificate of Analysis and Safety Data Sheet for lot-specific storage recommendations.
Is 4-Methyl-5,6-dihydro-2H-pyran-2-one suitable for use in Diels-Alder reactions?
Yes, the endocyclic alpha,beta-unsaturated lactone system makes 4-Methyl-5,6-dihydro-2H-pyran-2-one a viable dienophile in Diels-Alder cycloadditions. This reactivity is exploited in synthetic routes targeting complex cyclic natural products and enantioenriched lactone frameworks.
What safety precautions are required when handling this compound?
Handle 4-Methyl-5,6-dihydro-2H-pyran-2-one in a well-ventilated fume hood wearing chemical-resistant gloves, a laboratory coat, and safety glasses. Avoid inhaling vapors or allowing skin and eye contact. Consult the full SDS from Aladdin Scientific before use.
References
- March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. General reference for Michael addition and lactone reactivity.
- Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry. Oxford University Press. Reference for Diels-Alder reactions and unsaturated lactone chemistry.
- Aladdin Scientific. Product page and Certificate of Analysis for 4-Methyl-5,6-dihydro-2H-pyran-2-one, SKU A1062456.
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
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