1-Octyn-3-ol
[CAS# 818-72-4]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty alcohol
• Name: 1-Octyn-3-ol
• Synonyms: oct-1-yn-3-ol
• Molecular Formula: C₈H₁₄O
• Molecular Weight: 126.20
• CAS Registry Number: 818-72-4
• EC Number: 212-455-4
• SMILES: CCCCCC(C#C)O

Properties

• Density: 0.9±0.1 g/cm³ Calc.^*, 0.865 g/mL (Expl.)
• Melting point: -60 ºC (Expl.)
• Boiling point: 169.6±8.0 ºC 760 mmHg (Calc.)^*, 180 - 181 ºC (Expl.)
• Flash point: 63.9 ºC (Calc.)^*, 63 ºC (Expl.)
• Index of refraction: 1.453 (Calc.)^*, 1.442 (Expl.)

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

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Hazard Statements: H302-H400
• Precautionary Statements: P264-P270-P273-P301+P317-P330-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400

Discovory and Applicatios

1-Octyn-3-ol is an organic compound classified as an alkynyl alcohol, featuring an eight-carbon linear chain with a triple bond between the first and second carbon atoms and a hydroxyl group (–OH) attached to the third carbon. Its molecular formula is C₈H₁₄O, reflecting the combination of an alkyne functional group and an alcohol moiety within the same molecule.

The synthesis of 1-octyn-3-ol typically involves the addition of acetylene or acetylide ions to appropriate electrophilic intermediates, such as aldehydes or epoxides, to introduce the triple bond and hydroxyl functionalities in the correct positions. For example, nucleophilic addition of an acetylide anion to a 3-oxoalkane derivative can produce the desired alkynyl alcohol after subsequent protonation. Alternative synthetic routes may involve partial reduction of polyunsaturated precursors or selective functional group transformations starting from linear alkynes.

1-Octyn-3-ol is utilized in organic synthesis as a versatile intermediate due to its dual reactive sites: the terminal alkyne allows for participation in coupling reactions such as Sonogashira or Glaser coupling, while the hydroxyl group offers sites for further derivatization, including esterification, etherification, or oxidation. This multifunctionality makes it valuable in constructing complex molecules in pharmaceuticals, agrochemicals, and specialty materials.

In flavor and fragrance chemistry, alkynyl alcohols like 1-octyn-3-ol contribute to the aroma profiles of natural and synthetic products. Their unique structure imparts distinct olfactory characteristics, often described as fatty, green, or floral notes, depending on the molecular context. Such properties lead to their incorporation into fragrance formulations and flavor enhancers.

Analytical characterization of 1-octyn-3-ol involves nuclear magnetic resonance (NMR) spectroscopy to confirm the presence and position of the alkyne and hydroxyl groups within the carbon chain. Infrared (IR) spectroscopy detects characteristic absorption bands of the alkyne C≡C stretch near 2100–2200 cm^–1 and the O–H stretch around 3200–3600 cm^–1. Gas chromatography–mass spectrometry (GC-MS) is employed for purity analysis and identification, especially important for quality control in synthesis and application.

Safety considerations include the compound’s flammability and potential irritant effects upon skin or eye contact. Standard laboratory precautions such as wearing gloves, eye protection, and working in well-ventilated areas are recommended. Due to its chemical reactivity, especially the terminal alkyne, care should be taken to avoid uncontrolled reactions or exposure to reactive chemicals.

In summary, 1-octyn-3-ol is an alkynyl alcohol with a terminal triple bond and a hydroxyl group on the third carbon of an eight-carbon chain. It serves as a valuable intermediate in organic synthesis and finds uses in flavor and fragrance industries. Well-established synthetic methodologies, comprehensive analytical techniques, and standard safety protocols support its use in various chemical and industrial contexts.

References

2019. Identification of the aggregation-sex pheromone of Plagionotus arcuatus ssp. arcuatus (Coleoptera: Cerambycidae) from two geographically separated European populations. Die Naturwissenschaften, 106(5-6).
DOI: 10.1007/s00114-019-1612-2

2007. Evaluation of the enantiomers of 1-octen-3-ol and 1-octyn-3-ol as attractants for mosquitoes associated with a freshwater swamp in Florida, U.S.A. Medical and Veterinary Entomology, 21(4).
DOI: 10.1111/j.1365-2915.2007.00697.x

2005. (Z, Z)-6,9-Heneicosadien-11-One: Major Sex Pheromone Component Of Painted Apple Moth, Teia anartoides. Journal of Chemical Ecology, 31(3).
DOI: 10.1007/s10886-005-2048-z