3,7-DIMETHYLOCT-6-EN-1-YN-3-OL

3,7-Dimethyloct-6-en-1-yn-3-ol is an unsaturated tertiary propargylic alcohol commonly known as dehydrolinalool.
It is an important C10 intermediate in the industrial synthesis of linalool, citral, ionones, aroma chemicals, and selected vitamin and pharmaceutical intermediates.
Its structure combines a terminal alkyne, an alkene, and a tertiary alcohol, enabling selective hydrogenation, catalytic rearrangement, and multistep carbon-chain transformations.

CHEMICAL IDENTITY

Preferred Chemical Name: 3,7-Dimethyloct-6-en-1-yn-3-ol
Common Name: Dehydrolinalool
CAS Number: 29171-20-8
EC Number: 249-482-6
Molecular Formula: C10H16O
Molar Mass: 152.23 g/mol
Exact Mass: 152.1201 g/mol
SMILES: C#CC(C)(O)CCC=C(C)C
InChIKey: YWTIDNZYLFTNQQ-UHFFFAOYSA-N
Chemical Class: Unsaturated tertiary alcohol
Structural Type: Acyclic monoterpenoid propargylic alcohol
Stereochemistry: Racemic material containing the R and S configurations at carbon 3

SYNONYMS

Dehydrolinalool
Dehydro-beta-linalool
Dehydro-β-linalool
Beta-dehydrolinalool
β-Dehydrolinalool
Dehydro-linalool
Linalool, dehydro-
Beta-linalool, dehydro-
β-Linalool, dehydro-
2-Dehydrolinalool
DLL
(±)-Dehydrolinalool
Racemic dehydrolinalool
3,7-Dimethyl-6-octen-1-yn-3-ol
6-Octen-1-yn-3-ol, 3,7-dimethyl-
3,7-Dimethyl-3-hydroxy-6-octen-1-yne
3-Hydroxy-3,7-dimethyloct-6-en-1-yne

IDENTITY CONTROL

The name dehydrolinalool is sometimes used for structurally different unsaturated alcohols.
Commercial orders should identify this product by the systematic name 3,7-dimethyloct-6-en-1-yn-3-ol, CAS 29171-20-8, molecular formula C10H16O, and the presence of a terminal alkyne group.
The CAS-defined acetylenic alcohol should not be confused with hotrienol or other non-acetylenic trienol materials that may carry similar common names.

MOLECULAR STRUCTURE AND CHEMICAL CHARACTER

3,7-Dimethyloct-6-en-1-yn-3-ol contains a terminal ethynyl group adjacent to a tertiary alcohol center.
The molecule also contains an isolated carbon-carbon double bond near the opposite end of the carbon chain.
Carbon 3 is stereogenic because it is attached to hydroxyl, methyl, ethynyl, and substituted hydrocarbon groups.
CAS 29171-20-8 normally represents racemic dehydrolinalool unless an enantiomerically defined grade is specified.

The terminal alkyne provides a controlled entry point for partial hydrogenation and catalytic rearrangement.
The tertiary alcohol and remote alkene must be preserved during selective processing when linalool or citral is the target product.

COMMERCIAL SIGNIFICANCE

Dehydrolinalool is a strategic intermediate connecting methylheptenone chemistry with linalool, citral, pseudoionone, ionones, and downstream terpene derivatives.
Its greatest commercial value comes from the ability to transform the terminal alkyne selectively while retaining the rest of the C10 carbon skeleton.
Process selectivity strongly influences yield, product color, odor, catalyst consumption, and downstream purification requirements.
The material is primarily handled in closed chemical-manufacturing systems rather than used directly as a general-purpose formulation ingredient.

PRODUCTION

The principal manufacturing route is the ethynylation of 6-methyl-5-hepten-2-one, commonly called methylheptenone, with acetylene.
The reaction is performed under strongly basic acetylide-forming conditions.

Traditional industrial processes employ acetylene dissolved in liquid ammonia with potassium hydroxide or another alkaline catalyst.
Nucleophilic addition of the acetylide species to the methylheptenone carbonyl group produces the tertiary propargylic alcohol structure.

After reaction completion, acetylene and ammonia are removed and recovered through controlled process operations.
The crude organic phase is washed to remove inorganic residues and water-soluble by-products.
Dehydrolinalool is subsequently purified by reduced-pressure distillation or equivalent controlled separation.

Efficient temperature control limits secondary reactions, color formation, dimer production, and accumulation of heavy boiling material.
Residual methylheptenone, cyclic alcohol by-products, light solvents, water, dehydrolinalool dimers, and heavy ends are important process-quality parameters.

PHYSICAL AND CHEMICAL PROPERTIES

Physical Form: Liquid
Appearance: Clear, colorless to pale yellow liquid
Odor: Floral and flowery
Boiling Range: Approximately 191–198 °C at atmospheric pressure
Reduced-Pressure Boiling Range: Approximately 89–93 °C at 16 mbar
Melting or Freezing Point: Approximately −57 °C
Density: Approximately 0.879 g/cm3 at 20 °C
Refractive Index: Approximately 1.46
Flash Point: Approximately 80–85 °C, closed cup
Autoignition Temperature: Approximately 270 °C
Water Solubility: Approximately 2.45 g/L at 20 °C
Log Kow: Approximately 2.61 at 25 °C
Combustibility: Combustible liquid
The product can gradually develop color or deteriorate when exposed for extended periods to air, heat, or intense light.

CHEMICAL REACTIVITY AND DERIVATIVE CHEMISTRY

Controlled partial hydrogenation converts the terminal alkyne into a vinyl group and produces linalool.
The hydrogenation catalyst and operating conditions must minimize overhydrogenation of the newly formed double bond and the existing alkene.

Further hydrogenation can produce more highly saturated terpene alcohol derivatives when required by the downstream process.
Catalytic rearrangement of the propargylic alcohol provides access to citral-type aldehydes.
This transformation is related to the Meyer–Schuster rearrangement of propargylic alcohols into unsaturated carbonyl compounds.
Citral can be condensed with acetone to form pseudoionone.

Pseudoionone can then undergo acid-catalyzed cyclization to produce alpha-ionone, beta-ionone, and related aroma chemicals.
The terminal alkyne also supports specialized coupling, addition, and catalytic transformation chemistry in fine-chemical research.
Strong oxidizing conditions can attack the alcohol, alkyne, or alkene functionality and should be excluded from normal storage and transfer operations.

APPLICATIONS AND INDUSTRIES

Linalool manufacture

Selective semihydrogenation of dehydrolinalool is a major industrial route to linalool.
The process converts the terminal alkyne into the terminal alkene required for the linalool structure.
High selectivity is essential because excessive hydrogenation reduces linalool yield and generates saturated by-products.
Low catalyst-poison levels, controlled water content, and a defined heavy-end profile support stable hydrogenation performance.
Linalool is widely used in fragrance chemistry and as an intermediate for linalyl esters, terpene alcohols, and other aroma ingredients.

Citral production

Dehydrolinalool can be catalytically rearranged to produce citral.
Citral is an important citrus-odor material and a versatile intermediate for aroma chemicals, ionones, and other terpene derivatives.
Control of acidity, reaction temperature, residence time, and water content is important for suppressing polymeric and high-boiling by-products.
A low level of residual methylheptenone and dimeric material supports efficient downstream citral purification.

Pseudoionone and ionone synthesis

Citral derived from dehydrolinalool can be condensed with acetone to form pseudoionone.
Pseudoionone is a key intermediate for the production of alpha-ionone, beta-ionone, and related cyclic aroma compounds.
Ionones provide violet, woody, and floral odor characteristics in fragrance applications.
Beta-ionone chemistry also contributes to industrial routes for vitamin A and carotenoid intermediates.

Fragrance and aroma-chemical intermediates

Dehydrolinalool supports the manufacture of linalool, citral, ionones, selected terpene alcohols, and terpene esters.
These derivatives are used in perfume compounds, soaps, detergents, household products, personal-care fragrances, and industrial odor systems.
Dehydrolinalool is normally converted into the required aroma ingredient before incorporation into a finished formulation.
Its floral odor also permits specialized direct fragrance use when the purchased grade carries the required identity, purity, and use-specific documentation.

Vitamin intermediate manufacture

The C10 terpene skeleton is valuable in multistep synthesis routes leading to vitamin and carotenoid side-chain intermediates.
Dehydrolinalool-derived linalool, citral, and ionone chemistry contributes to routes associated with vitamin A manufacture.
Related chain-extension and hydrogenation chemistry can contribute to intermediates used in vitamin E and vitamin K production.
Dehydrolinalool functions as a chemical building block in these processes and is not itself a vitamin-active ingredient.

Pharmaceutical and fine-chemical synthesis

The compound provides a compact molecule containing a terminal alkyne, tertiary alcohol, internal alkene, and defined stereogenic center.
This combination is useful for selective hydrogenation, catalytic rearrangement, coupling, and carbon-chain construction studies.
It can serve as a starting material or reference intermediate in terpene synthesis, catalyst evaluation, and reaction-selectivity development.
Stereochemically specified material can be used where enantiomeric composition influences the target process or product.

Catalyst and process development

Dehydrolinalool is a useful substrate for evaluating selective alkyne hydrogenation catalysts.
The process must discriminate between the terminal triple bond, newly produced terminal double bond, and existing internal double bond.
Catalyst activity can be assessed through conversion, linalool selectivity, overhydrogenation, isomerization, and heavy-product formation.
The material is also suitable for evaluating propargylic-alcohol rearrangement catalysts and continuous-process operating conditions.

GRADE SELECTION

Technical Intermediate Grade

Technical grades are intended for hydrogenation, rearrangement, and downstream industrial synthesis.
Key purchasing criteria include assay, residual methylheptenone, dimer content, heavy ends, water, color, and catalyst-poisoning impurities.

High-Purity Synthesis Grade

High-purity grades are used for fine-chemical synthesis, analytical work, catalyst screening, and processes requiring a tightly controlled chromatographic profile.
These grades place greater emphasis on GC assay, individual impurity limits, water content, and color.

Fragrance Grade

Fragrance-oriented grades require controlled identity, odor, color, purity, and composition.
Documentation must clearly distinguish the acetylenic material from other substances marketed under the dehydrolinalool name.
Stereochemically Specified Grade
Standard CAS 29171-20-8 material is generally racemic.
Chiral applications require an explicitly defined enantiomer, optical rotation, and enantiomeric composition.

PROCESS SELECTION CONSIDERATIONS

Hydrogenation processes require material with low concentrations of sulfur compounds, heavy metals, residual catalyst species, and other catalyst poisons.
Residual methylheptenone and light components can influence reaction selectivity and downstream fractionation.
Dimeric and heavy-boiling impurities can accumulate in reboilers, catalysts, and recycle streams.
Water content should be controlled where the catalyst system or rearrangement chemistry is moisture-sensitive.

Color and odor are useful indicators of storage history, oxidation, and heavy-product formation.
The product should be transferred through clean, dry, closed equipment to preserve its purity profile.

QUALITY CONTROL

Typical quality controls include appearance, color, odor, identity, chromatographic assay, density, refractive index, and water content.
Gas chromatography with flame-ionization detection is commonly used for assay and quantitative impurity profiling.

Gas chromatography with mass-spectrometric detection supports structural identification of unknown peaks.
Karl Fischer analysis is suitable for controlling trace water.
Chiral gas chromatography can determine the enantiomeric composition of stereochemically specified grades.

Additional controls can include residual methylheptenone, light solvents, cyclic by-products, dehydrolinalool dimer, heavy ends, acidity, and trace metals.
A representative certificate of analysis should identify the test methods, numerical results, specification limits, batch number, and manufacturing date.

SAFETY INFORMATION

Signal Word: Warning
Dehydrolinalool is a combustible liquid.

It causes skin irritation.
It causes serious eye irritation.
It is suspected of damaging fertility or the unborn child.

It is harmful to aquatic life with long-lasting effects.
Personnel should avoid direct contact with the liquid and prevent inhalation of vapor, aerosol, or process mist.
Reproductive-hazard controls should include restricted access, documented training, closed handling, effective ventilation, and occupational-health procedures.

Exposure should be controlled through enclosure, local exhaust ventilation, and suitable personal protective equipment.
Chemical-resistant gloves, protective clothing, safety goggles, and face protection should be selected for the operation.
Respiratory protection is required when engineering controls cannot adequately control vapor or mist exposure.
Food, beverages, and tobacco products should be excluded from handling areas.
Hands and exposed skin should be washed thoroughly after handling.

FIRST AID MEASURES

Eye Contact

Rinse the eyes cautiously with clean water for several minutes.
Remove contact lenses when they can be removed easily and continue rinsing.
Obtain medical attention for persistent irritation or significant exposure.

Skin Contact

Remove contaminated clothing and footwear.
Wash affected skin thoroughly with soap and water.
Obtain medical attention if irritation develops or persists.

Inhalation

Move the affected person to fresh air and keep them comfortable for breathing.
Obtain medical attention if coughing, breathing difficulty, dizziness, or other symptoms occur.

Ingestion

Rinse the mouth with water.
Do not give anything by mouth to an unconscious person.
Contact a physician or poison information center promptly.
Reproductive-Hazard Exposure
Obtain medical advice following significant exposure or when there is concern regarding fertility or pregnancy.

FIRE-FIGHTING MEASURES

Suitable extinguishing media include alcohol-resistant foam, dry chemical powder, carbon dioxide, and water spray.
Water spray can be used to cool closed containers exposed to fire.
Fire can produce irritating or toxic combustion products, including carbon monoxide and carbon dioxide.

Firefighters should use self-contained breathing apparatus and full protective equipment.
Containers exposed to heat should be cooled from a protected position.
Contaminated fire water should be contained and prevented from entering drains or natural waterways.

ACCIDENTAL RELEASE MEASURES

Eliminate flames, sparks, hot surfaces, and other ignition sources.
Ventilate the affected area and restrict access to trained personnel.

Wear appropriate gloves, protective clothing, eye protection, and respiratory protection when required.
Stop the leak when this can be done safely.
Contain the liquid with inert absorbent material and transfer collected waste into a compatible, labeled container.
Prevent the product and contaminated cleaning materials from entering drains, soil, or surface water.
Wash the affected area only after the bulk material has been collected and contained.

HANDLING

Use closed transfer systems wherever practical.
Provide local exhaust ventilation at sampling, charging, filtration, and filling points.
Avoid breathing vapor, aerosol, or mist.

Avoid contact with the skin, eyes, and clothing.
Use grounded and bonded equipment during bulk transfer.
Keep ignition sources away from handling and storage areas.
Use non-sparking equipment where a flammable atmosphere could develop.

Minimize prolonged exposure to air and light during sampling and repacking.
Do not return contaminated or sampled material to the original container.

STORAGE

Store the product in a cool, dry, well-ventilated, and controlled area.
Keep containers tightly closed and protected from direct sunlight, heat, sparks, and flames.

Refrigerated high-purity packs are commonly maintained at 2–8 °C.
Segregate the product from strong oxidizing agents and incompatible metals.
Use chemically compatible containers, seals, pumps, valves, and transfer lines.

Maintain clean and dry storage equipment to limit water uptake and contamination.
Inspect stored material for closure integrity, leakage, color development, and evidence of contamination.

ENVIRONMENTAL CONSIDERATIONS

Dehydrolinalool is harmful to aquatic life with long-lasting effects.
Although the substance is biodegradable under standard screening conditions, concentrated releases can adversely affect aquatic systems.
Process water, cleaning liquids, spills, and residues should be collected for controlled treatment or disposal.
The product should never be discharged directly into drains, soil, groundwater, or surface water.

PACKAGING AND LOGISTICS

Dehydrolinalool is commonly supplied in tightly sealed small containers or industrial drums manufactured from compatible materials.
Packaging should protect the product from contamination, excessive headspace air, moisture, heat, and light.
Bulk movement should use closed, grounded transfer equipment and documented contamination controls.
Packages should carry the exact chemical identity, CAS number, batch number, net quantity, hazard labeling, and traceability information.

QUALITY AND PROCUREMENT DOCUMENTATION

Commercial evaluation should include the certificate of analysis, safety data sheet, technical data sheet, manufacturing traceability, and impurity profile.
Use-specific procurement may also require composition statements, inventory declarations, fragrance documentation, and regulatory compliance records.
The purchase specification should define assay, water, color, residual methylheptenone, individual process impurities, dimer content, and heavy ends.

Chiral composition should be included when an enantiomerically controlled process is involved.
The systematic name and CAS number should appear together on purchase orders to prevent substitution with hotrienol or another similarly named material.

ATAMAN KIMYA

Ataman Kimya supports the sourcing and technical evaluation of 3,7-dimethyloct-6-en-1-yn-3-ol for linalool, citral, ionone, fragrance-intermediate, vitamin-intermediate, and fine-chemical production.
Product selection can be aligned with the required assay, impurity profile, water content, stereochemical composition, packaging format, and downstream reaction.
Technical and commercial requests should specify the intended transformation, annual quantity, preferred packaging, required documentation, and destination.

+90 216 577 10 10

info@atamankimya.com