Dicyclopropyl ketone
[CAS 1121-37-5]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty ketone (including enol)
• Name: Dicyclopropyl ketone
• Synonyms: Cyclopropyl ketone
• Molecular Formula: C₇H₁₀O
• Molecular Weight: 110.15
• CAS Registry Number: 1121-37-5
• EC Number: 214-331-5
• SMILES: C1CC1C(=O)C2CC2

Properties

• Density: 1.2±0.1 g/cm³ Calc.^*, 0.968 g/mL (Expl.)
• Boiling point: 161.0±8.0 °C 760 mmHg (Calc.)^*, 160 - 162 °C (Expl.)
• Flash point: 39.4 °C (Calc.)^*, 39 °C (Expl.)
• Index of refraction: 1.558 (Calc.)^*, 1.467 (Expl.)

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

Safety Data

• Hazard Symbols: GHS02 WarningGHS02
• Risk Statements: H226
• Safety Statements: P210-P233-P240-P241-P242-P243-P280-P303+P361+P353-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
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Skin corrosion	Skin Corr.	1	H314
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - single exposure	STOT SE	3	H335

• Transport Information: UN 1224

Discovery and Applications

Dicyclopropyl ketone is an organic compound belonging to the class of dialkyl ketones in which the carbonyl carbon is bonded to two cyclopropyl groups. It can be viewed as a highly strained, conformationally constrained ketone in which the substituents on the carbonyl are three-membered carbocyclic rings. The presence of cyclopropyl substituents introduces significant ring strain effects and unique electronic properties compared with acyclic alkyl ketones.

Ketones have been a central functional group in organic chemistry since the early development of structural organic theory in the nineteenth century, when carbonyl-containing compounds were systematically classified and their reactivity patterns established. The carbonyl group is characterized by a polarized carbon–oxygen double bond, which makes the carbon atom electrophilic and capable of undergoing nucleophilic addition reactions. Dicyclopropyl ketone follows these general principles but exhibits modified behavior due to the presence of cyclopropyl rings.

Cyclopropyl groups are known for their unusual electronic structure resulting from significant angle strain in the three-membered ring. The carbon–carbon–carbon bond angles are compressed relative to ideal tetrahedral geometry, leading to increased energy and partial bending of the bonding orbitals. This strain can result in enhanced reactivity in adjacent functional groups and can influence the stability of intermediates formed during chemical reactions. When two cyclopropyl groups are attached to a carbonyl carbon, as in dicyclopropyl ketone, these effects are amplified in the immediate chemical environment of the carbonyl group.

Compounds containing cyclopropyl substituents have been widely studied in organic chemistry and medicinal chemistry due to their ability to modulate molecular shape and electronic distribution. Cyclopropyl groups are often used as bioisosteres for more flexible alkyl groups because they introduce conformational restriction while maintaining relatively similar steric volume. In ketone systems, this can influence both reactivity and interactions with biological targets or catalytic systems.

The synthesis of dicyclopropyl ketone is typically achieved through established carbonyl-forming reactions involving cyclopropyl-containing precursors. Common approaches include acylation reactions using cyclopropyl organometallic reagents or derivatives of carboxylic acids that incorporate cyclopropyl groups. Ketone formation through nucleophilic acyl substitution or controlled oxidation of secondary alcohol precursors is also consistent with general ketone synthesis methodologies. These synthetic strategies reflect the broader toolkit of carbonyl chemistry developed throughout the twentieth century.

The carbonyl group in dicyclopropyl ketone retains its fundamental electrophilic character, allowing it to participate in nucleophilic addition reactions with a variety of reagents such as hydrides, organometallic species, and nitrogen or oxygen nucleophiles. However, the electronic influence of the cyclopropyl rings can alter the reactivity profile compared with simple dialkyl ketones. Cyclopropyl groups are known to exhibit partial pi-character due to bent bonding, which can interact with adjacent functional groups and influence reaction pathways.

From a structural perspective, dicyclopropyl ketone is a relatively rigid molecule due to the constrained geometry of the cyclopropyl rings. This rigidity can reduce conformational flexibility compared with open-chain dialkyl ketones. The overall molecular shape is compact, with the carbonyl group centrally positioned between two strained ring systems. This can affect intermolecular interactions and packing behavior in the solid state.

Physicochemically, ketones of this type typically exhibit moderate polarity due to the presence of the polar carbonyl group. The cyclopropyl substituents contribute nonpolar hydrocarbon character, but their strained nature can slightly modify electronic distribution. As a result, dicyclopropyl ketone is expected to show limited water solubility but good solubility in organic solvents. Its volatility and boiling behavior are influenced by the balance between molecular weight, polarity, and intermolecular interactions.

In broader chemical research, cyclopropyl-substituted ketones are of interest as intermediates in synthetic organic chemistry and as probes for studying the effects of ring strain on reactivity. The combination of a reactive carbonyl group with strained ring systems provides a useful platform for investigating reaction mechanisms, particularly in nucleophilic addition and rearrangement processes.

Overall, dicyclopropyl ketone is a strained dialkyl ketone characterized by two cyclopropyl groups attached to a central carbonyl carbon. Its significance lies in the interplay between carbonyl chemistry and cyclopropyl ring strain, which influences its reactivity, structural properties, and utility as a building block in organic synthesis and mechanistic studies.

References

2026. Photoredox N-heterocyclic carbene catalysis via radicals. Science China Chemistry.
DOI: 10.1007/s11426-025-3107-4

2025. Organocatalysed three-component modular synthesis of BN isosteres and BN-2,1-azaboranaphthalenes via Wolff-type rearrangement. Nature Chemistry.
URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12768968

2025. Efficient and modular synthesis of ibogaine and related alkaloids. Nature Chemistry.
URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11952118