isospirene

Isospirene is a spirocyclic organic compound characterized by the molecular formula C₁₃H₂₀O. It belongs to the class of oxygen-containing spiro compounds with a distinctive structural arrangement featuring a 1-oxaspiro[4.5]deca-3,6-diene framework and four methyl substituents at positions 2, 6, 9, and 10. This compound exhibits a fruity odor reminiscent of black currant when diluted at 10% in dipropylene glycol, making it notable in fragrance chemistry. Known under various synonyms such as 2,6,9,10-tetramethyl-1-oxaspiro[4.5]deca-3,6-diene, isospirene is documented in chemical databases including PubChem. Typically, it is sourced through synthetic organic methodologies designed to produce spirocyclic aroma chemicals intended for scent applications rather than natural extraction.

Isospirene occurs primarily as a synthetic fragrance ingredient rather than a naturally occurring substance in biological systems. It is valued for its distinctive fruity aroma and is applied predominantly as a fragrance agent in perfumes and related scented products. Its use is regulated under IFRA (International Fragrance Association) standards (Global), which provide guidelines for safe inclusion rates in formulations to ensure consumer safety. This compound’s unique olfactory profile and chemical stability allow it to enhance or modify fragrance compositions, typically contributing fruity black currant notes. Due to its specific properties and regulatory restrictions, isospirene is not employed as a flavoring agent but remains a component within the fragrance industry to create complex scent accords.

Isospirene exhibits a boiling range between 258 and 260°C at standard atmospheric pressure (760 mm Hg), indicating moderate volatility suitable for fragrance evaporation. Its estimated log P value of approximately 3.98 suggests moderate lipophilicity, which supports solubility in lipophilic solvents such as alcohol and limited solubility in water (approximately 6.365 mg/L at 25°C estimated). The vapor pressure recorded at 0.021 mmHg at 25°C confirms a low volatility under ambient conditions, contributing to its persistence in scent formulations. The flash point measured at 225°F (approximately 107°C) defines its flammability characteristics relevant to handling and storage. These physicochemical traits influence its performance in perfume compositions, affecting factors such as diffusion, longevity, and blending compatibility with other ingredients.

(IUPAC):	Atomic Weights of the Elements 2011 (pdf)
Videos:	The Periodic Table of Videos
tgsc:	Atomic Weights use for this web site
(IUPAC):	Periodic Table of the Elements
HMDB (The Human Metabolome Database):	HMDB36022
FooDB:	FDB014840
ChemSpider:	View
Wikipedia:	View

Safety information

Hazards identification
Classification of the substance or mixture
GHS Classification in accordance with 29 CFR 1910 (OSHA HCS)
None found.
GHS Label elements, including precautionary statements
Pictogram
Hazard statement(s)
None found.
Precautionary statement(s)
None found.
Oral/Parenteral Toxicity:
Not determined
Dermal Toxicity:
Not determined
Inhalation Toxicity:
Not determined

Safety in use information

Category:
fragrance agents
RIFM Fragrance Material Safety Assessment: Search
IFRA Code of Practice Notification of the 49th Amendment to the IFRA Code of Practice
Recommendation for isospirene flavor usage levels up to:
	not for flavor use.

Safety references

EPI System: View

AIDS Citations:Search

Cancer Citations:Search

Toxicology Citations:Search

EPA Substance Registry Services (TSCA):71078-31-4

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :116740

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:2

3,6,7,10-tetramethyl-4-oxaspiro[4.5]deca-1,9-diene

Chemidplus:0071078314