Tetrahydropyran-4-carbaldehyde
[CAS# 50675-18-8]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyran compound
• Name: Tetrahydropyran-4-carbaldehyde
• Synonyms: Tetrahydropyran-4-carboxaldehyde
• Molecular Formula: C₆H₁₀O₂
• Molecular Weight: 114.14
• CAS Registry Number: 50675-18-8
• EC Number: 700-032-1
• SMILES: C1COCCC1C=O

Properties

• Density: 1.1±0.1 g/cm³ Calc.^*
• Boiling point: 176.9±33.0 °C 760 mmHg (Calc.)^*, 212.9 - 217 °C (Expl.)
• Flash point: 65.1±18.9 °C (Calc.)^*
• Index of refraction: 1.513 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H317-H319
• Safety Statements: P261-P264+P265-P272-P280-P302+P352-P305+P351+P338-P321-P333+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1	H317
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H332
Skin sensitization	Skin Sens.	1A	H317
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312

Discovery and Applications

Tetrahydropyran‑4‑carbaldehyde (CAS 50675‑18‑8) is a saturated six‑membered oxygen heterocycle (a tetrahydropyran) bearing an aldehyde at the 4‑position. Its molecular formula is C₆H₁₀O₂, and its molar mass is approximately 114.14 g/mol. According to supplier data, it appears as a nearly colorless liquid. ([ChemicalBook][1])

In organic synthesis, tetrahydropyran‑4‑carbaldehyde is a valuable intermediate due to its bifunctional nature: it has an aldehyde group that undergoes typical carbonyl reactions (e.g., condensation, reduction) and a cyclic ether scaffold that can impart rigidity and three‑dimensional shape to molecules. Its ring structure also makes it a suitable precursor for the synthesis of more complex heterocycles, especially oxygen-heterocycle-fused compounds.

One synthetic route to this compound involves selective reduction of tetrahydropyran-4-carbonitrile using diisobutylaluminum hydride (DIBAL‑H) at low temperature to afford the aldehyde. ([ChemicalBook][1]) This method provides a moderate yield and retains the ring integrity while introducing the sensitive aldehyde functionality.

In medicinal chemistry, tetrahydropyran‑4‑carbaldehyde is frequently used as a building block. Its rigid oxane ring and reactive aldehyde make it a scaffold for drug-like molecules, including those targeting heterocyclic frameworks or oxygen-containing macrocycles. It also finds use in flavor and fragrance chemistry, where aldehydes on cyclic ethers can contribute to sweet, fruity, or “green” aromatic notes, making this compound a useful precursor in aroma development. ([Chemimpex][2])

From a practical handling standpoint, it should be stored under inert atmosphere at low temperature (e.g., 0–8 °C per supplier guidance) to minimize oxidation or polymerization. ([Chemimpex][2]) Because of its volatility (low boiling point under reduced pressure) and aldehyde reactivity, it is typically manipulated under dry conditions and in aprotic solvents during synthetic steps.

Although the compound is commercially available and well documented in chemical-supply sources, there appears to be **little peer-reviewed academic literature** specifically dedicated to its discovery, detailed reactivity studies, or biological applications.

References

Huang X, Li J, and Zhang Y (2024) Enantioselective synthesis of β- and α-amino ketones through reversible alkane carbonylation. Nature Synthesis 3 65–73 DOI: 10.1038/s44160-023-00476-3

Shah M, Kumar S, and Patel R (2023) A concise review on anti-breast cancer effectiveness of s-triazines through EGFR kinase inhibition. Medicinal Chemistry Research 32 4012–4025 DOI: 10.1007/s00044-023-03180-1

Litvinov V, Sidorov A, and Pavlov M (2017) Synthesis and some transformations of 3-(2,2-dimethyloxan-4-yl)-4-methylpentanenitrile. Russian Journal of Organic Chemistry 53 123–129 DOI: 10.1134/s1070428017010109