3,3-Dimethylcyclohexanone
[CAS 2979-19-3]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty ketone (including enol)
• Name: 3,3-Dimethylcyclohexanone
• Molecular Formula: C₈H₁₄O
• Molecular Weight: 126.20
• CAS Registry Number: 2979-19-3
• EC Number: 628-905-1
• SMILES: CC1(CCCC(=O)C1)C

Properties

• Density: 0.9±0.1 g/cm³ Calc.^*, 0.91 g/mL (Expl.)
• Boiling point: 170.6±8.0 °C 760 mmHg (Calc.)^*, 174 - 175 °C (Expl.)
• Flash point: 50.1±10.7 °C (Calc.)^*, 59 °C (Expl.)
• Index of refraction: 1.438 (Calc.)^*, 1.449 (Expl.)

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

Safety Data

• Hazard Symbols: GHS02;GHS05 DangerGHS02
• Risk Statements: H226-H318
• Safety Statements: P210-P233-P240-P241-P242-P243-P264+P265-P280-P303+P361+P353-P305+P354+P338-P317-P370+P378-P403+P235-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Serious eye damage	Eye Dam.	1	H318
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335

• Transport Information: UN 1993

Discovery and Applications

3,3-Dimethylcyclohexanone is a substituted cyclohexanone belonging to the class of alicyclic ketones. It consists of a six-membered saturated carbon ring containing a ketone functional group and two methyl substituents attached to the carbon adjacent to the carbonyl position. The compound is an example of a branched cyclic ketone and is studied mainly as an intermediate in organic synthesis.

Cyclohexanone derivatives have been important compounds in organic chemistry because the cyclohexanone framework is a versatile structural unit found in many synthetic pathways. The development of substituted cyclohexanones occurred as chemists investigated methods for modifying cyclic ketone structures to obtain compounds with different physical and chemical properties. 3,3-Dimethylcyclohexanone belongs to this family of modified cyclohexanones and has been prepared through established synthetic methods used for the construction of substituted cyclic ketones.

The structure of 3,3-dimethylcyclohexanone contains a carbonyl group within the six-membered ring. The carbonyl carbon is the main reactive center of the molecule because it is electrophilic and can participate in reactions with nucleophiles. The two methyl groups attached to the 3-position modify the electronic and steric environment around the carbonyl group. These substituents increase the hydrocarbon character of the molecule and influence its behavior in chemical transformations.

The cyclohexanone ring is a saturated six-membered ring that can adopt different conformations, with the chair conformation being an important low-energy arrangement for many cyclohexane derivatives. The presence of two methyl groups at the same carbon introduces steric effects and influences the preferred conformational behavior of the molecule. The ring flexibility allows 3,3-dimethylcyclohexanone to participate in reactions where the spatial arrangement of substituents affects reaction outcomes.

The primary chemical importance of 3,3-dimethylcyclohexanone is its use as an intermediate in organic synthesis. Cyclic ketones are widely used as starting materials for the preparation of alcohols, hydrocarbons, heterocyclic compounds, and other functionalized molecules. The carbonyl group of 3,3-dimethylcyclohexanone can undergo typical ketone reactions, including reduction to produce corresponding alcohol derivatives and condensation reactions that form new carbon-carbon bonds.

The alpha carbon atoms adjacent to the carbonyl group are also important in synthetic chemistry because hydrogen atoms in these positions can participate in reactions involving enolate formation. Enolate intermediates derived from cyclic ketones are widely used in carbon-carbon bond-forming reactions. The methyl substituents in 3,3-dimethylcyclohexanone influence the accessibility and reactivity of these positions, which can affect the selectivity of synthetic transformations.

The compound has been used in research and chemical synthesis as a building block for producing more complex organic molecules. Substituted cyclohexanones are valuable intermediates in the preparation of specialty chemicals because their ring structures provide useful frameworks that can be further modified. Their applications are mainly associated with laboratory and industrial synthesis rather than direct consumer use.

In addition to its synthetic value, 3,3-dimethylcyclohexanone represents an important example for studying the relationship between molecular structure and reactivity in cyclic ketones. Research on substituted cyclohexanones has contributed to the understanding of steric effects, conformational behavior, and carbonyl chemistry in saturated ring systems.

Overall, 3,3-dimethylcyclohexanone is a substituted cyclic ketone whose importance comes from its role as an organic synthesis intermediate. Its carbonyl functionality, flexible cyclohexane framework, and methyl substitution pattern provide useful chemical characteristics for the preparation of other organic compounds and for studies of cyclic ketone reactivity.

References

2025. Green synthesis of pyrazole derivatives via one-pot three component Knoevenagel–Michael addition utilizing TiO2/RuO2/CuO as a ternary nanocatalytic system: characterization, DFT and molecular docking studies. Research on Chemical Intermediates.
DOI: 10.1007/s11164-025-05534-3

2022. Using Iron Complexes of N1,N2-Dimethyl-N1,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine and Other 1,1′-Bis(pyridin-2-ylmethyl)-2,2′-bipyrrolidine and 1,4-Dimethyl-7-[(6-methylpyridin-2-yl)methyl]-1,4,7-triazonane Ligands. Science of Synthesis.
URL: https://science-of-synthesis.thieme.com/app/text/?id=SD-126-00125