6,6-Dimethylbicyclo(3.1.1)Hept-2-Ene-2-Ethanol
[CAS# 35836-73-8]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Alcoholic spice >> Terpene alcohol
• Name: 6,6-Dimethylbicyclo(3.1.1)Hept-2-Ene-2-Ethanol
• Synonyms: (1R)-(-)-Nopol; 2-[(1R,5S)-6,6-dimethyl-2-bicyclo[3.1.1]hept-2-enyl]ethanol
• Molecular Formula: C₁₁H₁₈O
• Molecular Weight: 166.26
• CAS Registry Number: 35836-73-8
• EC Number: 252-744-2
• SMILES: CC1([C@H]2CC=C([C@@H]1C2)CCO)C

Properties

• Density: 1.0±0.1 g/cm³, Calc.^*, 0.974 g/mL (Expl.)
• Index of Refraction: 1.501, Calc.^*, 1.493 (Expl.)
• Boiling Point: 235.0±9.0 ºC (760 mmHg), Calc.^*, 230-240 ºC (Expl.)
• Flash Point: 98.9 ºC, Calc.^*, 98 ºC (Expl.)

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H317-H319-H335-H412
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P272-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin sensitization	Skin Sens.	1B	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2A	H319

Discovory and Applicatios

6,6-Dimethylbicyclo(3.1.1)hept-2-ene-2-ethanol is a saturated bicyclic monoterpenoid alcohol with the molecular formula C₁₀H₁₆O. It is structurally derived from the bicyclo[3.1.1]heptane skeleton, which is commonly observed in naturally occurring monoterpenes. This compound contains two methyl groups at the bridgehead position (carbon 6), a double bond at position 2, and a hydroxymethyl substituent at the same position, forming an allylic alcohol.

The compound is a synthetic derivative of compounds found in essential oils and turpentine-related substances. The core bicyclic framework is present in naturally occurring pinene and related terpenes, which are biosynthesized via the mevalonate pathway in plants. While 6,6-dimethylbicyclo(3.1.1)hept-2-ene-2-ethanol itself is not a natural product, it is chemically related to such natural bicyclic monoterpenes.

The synthesis of this compound is achieved through a multi-step process starting from α-pinene or other pinane-type compounds, involving rearrangement, oxidation, and reduction steps. One of the most common synthetic routes includes the introduction of a hydroxymethyl group via organometallic addition to a ketone precursor or by selective reduction of the corresponding carboxylic acid or ester derivative. The double bond in the structure facilitates further chemical modifications or functional group transformations.

6,6-Dimethylbicyclo(3.1.1)hept-2-ene-2-ethanol has been investigated for use in fragrance and flavor applications due to its structural similarity to aroma-active monoterpenoids. Bicyclic alcohols with low molecular weight and specific configurations are known to impart woody, pine-like, or resinous notes, making them valuable in perfumery and flavor formulation. However, the specific olfactory properties of this compound are less extensively documented than those of more widely used monoterpene alcohols such as borneol or linalool.

In materials science, derivatives of bicyclo[3.1.1]heptane-based alcohols have been used in polymer modification and the synthesis of specialty resins. Their rigid structure and potential reactivity at the hydroxyl group offer options for cross-linking in polymer networks or for introducing hydrophobic or sterically hindered features into materials.

The compound has also been explored as an intermediate in organic synthesis, particularly in the construction of sterically constrained frameworks. The strained bicyclic system is useful in studying reaction mechanisms that involve ring strain, regioselectivity, or stereoselectivity. Its hydroxyl group allows for further derivatization into esters, ethers, or other oxygen-containing functionalities, providing access to a variety of analogs and derivatives for structural activity relationship studies.

Analytical identification and characterization of 6,6-dimethylbicyclo(3.1.1)hept-2-ene-2-ethanol are conducted using standard techniques such as gas chromatography (GC), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). Its chemical behavior under acidic, basic, and oxidative conditions has been evaluated in the context of stability and reactivity relevant to formulation or synthetic applications.

Overall, 6,6-dimethylbicyclo(3.1.1)hept-2-ene-2-ethanol is primarily of interest in synthetic organic chemistry and product development involving monoterpene derivatives. Its applications are documented within well-defined research and industrial use cases, particularly those related to fine chemicals and performance materials. The available literature confirms its role as a stable, synthetically accessible compound with functional versatility for diverse chemical transformations.

References

2023. Design, synthesis and antifungal evaluation of novel nopol derivatives as potent laccase inhibitors. Pest Management Science, 79(7).
DOI: 10.1002/ps.7426

2021. Nopol-Based Quinoline Derivatives as Antiplasmodial Agents. Molecules (Basel, Switzerland), 26(4).
DOI: 10.3390/molecules26041008

2017. Biological properties of Hertia cheirifolia L. flower extracts and effect of the nopol on &alpa;-glucosidase. International Journal of Biological Macromolecules, 95.
DOI: 10.1016/j.ijbiomac.2016.12.008