80-71-7

Basic information

• Product Name: Methyl cyclopentenolone
• Synonyms: RARECHEM AQ C5 0001;FEMA 2700;CYCLOTENE;METHYL CYCLOPENTENOLONE;3-METHYL-2-HYDROXY-2-CYCLOPENTENONE;3-METHYL-2-CYCLOPENTENON-2-OL;2-HYDROXY-3-METHYLCYCLOPENT-2-ENONE;2-HYDROXY-3-METHYL-2-CYCLOPENTENE-1-ONE
• CAS NO: 80-71-7
• Molecular Formula: C₆H₈O₂
• Molecular Weight: 112.13
• EINECS: 201-303-2
• Product Categories: alcohol Flavor;insect pheromone
• Mol File: 80-71-7.mol
• Article Data: 26

Chemical Properties

• Melting Point: 104-108°C
• Boiling Point: 170.05°C (rough estimate)
• Flash Point: 100.7 °C
• Appearance: White crystalline powder
• Density: 1.0795 (rough estimate)
• Vapor Pressure: 0.978mmHg at 25°C
• Refractive Index: 1.4532 (estimate)
• Storage Temp.: Store at +2°C to +8°C.
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• PKA: 9.21±0.20(Predicted)
• Water Solubility: soluble
• CAS DataBase Reference: Methyl cyclopentenolone(CAS DataBase Reference)
• NIST Chemistry Reference: Methyl cyclopentenolone(80-71-7)
• EPA Substance Registry System: Methyl cyclopentenolone(80-71-7)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38-43
• Safety Statements: 26-36/37-24/25-22
• WGK Germany: 3
• RTECS: GY7298000
• Hazardous Substances Data: 80-71-7(Hazardous Substances Data)

Usage

Chemical Properties

Different sources of media describe the Chemical Properties of 80-71-7 differently. You can refer to the following data:
1. Methyl cyclopentenolone occurs in beechwood tar and has a caramel-like (burnt sugar) odor. It has been identified as a flavor component in food. Crystals of the compound usually contain 1 mol of water. Synthetic routes of production are of limited importance in comparison with isolation from beechwood tar. Homologs of cyclotene such as 3-ethyl-2-hydroxy-2-cyclopenten-1-one, C7H10O2, Mr 126.16, 2-hydroxy-3,4-dimethyl-2-cyclopenten-1-one, C7H10O2, Mr 126.16, and 2-hydroxy-3,5-dimethyl-2-cyclopenten-1-one, C7H10O2, Mr 126.16, are also used as flavor ingredients and have similar caramel-like properties. Cyclotene and its homologs are frequently used in flavor compositions for its caramel note, for example, in beverages and in confectionery.
2. Off-white solid

Occurrence

Reported to be found during the dry distillation of wood and in the corresponding tar oil. It has also been identified in fenugreek (FenaroWs Handbook of Flavor Ingredients, 1975).

Uses

Different sources of media describe the Uses of 80-71-7 differently. You can refer to the following data:
1. Methyl Cyclopentenolone is a flavoring agent that is a white crys- talline powder. it has a nutty odor suggesting a maple-licorice aroma when diluted. it is soluble in alcohol and propylene glycol, slightly soluble in most fixed oils, and sparingly soluble in water. it is obtained by synthesis. it is also termed 3-methyl-cyclopentane-1,2-dione.
2. Methyl cyclopentenolone may be used as an analytical reference standard for the quantification of the analyte in commercial products using different chromatography techniques.

Preparation

By ketonic hydrolysis of the corresponding dicarboxylic ester (Arctander, 1969)

Toxicity evaluation

The acute oral LD50 value in guinea-pigs was reported as 1.4 g/kg (Dow Chemical Company, 1953) and that in rats as > 1.85 g/kg, while the acute dermal LD50 value in guinea-pigs exceeded 2 g/kg (Moreno, 1976). Methylcyclopentenolone was lethal to mice and rats at ip doses of 0.5-1 g/kg (Shugaev, 1959), and at a concentration of 7 χ 10-4 m was toxic to cultured human leucocytes (Withers, 1966).

General Description

Methyl cyclopentenolone is one of the flavor compounds of maple syrup, coffee oil and wood smoke. It is reported to be one the key aroma compounds in Wasanbon sugar, contributing to the maple-like flavor. Methyl cyclopentenolone is also one of the major volatile compound formed during the thermal degradation of glucose.

InChI:InChI=1/C6H8O2/c1-4-2-3-5(7)6(4)8/h4H,2-3H2,1H3/t4-/m1/s1

Upstream product

• 30761-40-1 2-hydroxy-5-methylcyclopentanone 
• 65313-49-7 1-acetoxy-2,5-hexanedione 
• 137051-86-6 2-methyl-2-(trimethylsilyl-oxy)-glutaric acid dimethyl ester 
• 14496-35-6 N,N-dimethyl-1-(5-methylfuran-2-yl)methanamine 
• 534-22-5 2-methylfuran 
• 67-47-0 5-hydroxymethyl-2-furfuraldehyde 
• 65313-46-4 1-hydroxyl-2,5-hexanedione 
• 27583-37-5 3-methylcyclopentane-1,2-diol 
• 1188307-87-0 2-methyl-4-propoxypenta-1,4-dien-3-one 
• 57964-61-1 3-methyl-2-oxo-cyclopentanecarboxylic acid methyl ester 
• 123-38-6 propionaldehyde 
• 78-93-3 butanone 
• 14189-85-6 2-methoxy-3-methylcyclopent-2-en-1-one 
• 73923-18-9 2-chloro-3-methyl-2-cyclopenten-1-one 

Downstream Products

• 100813-26-1 tetrahydro-2-methyl-5-oxo-2-furancarboxylic acid methyl ester 
• 100813-24-9 methyl 4-carboxy-2-hydroxy-2-methylbutanoate 
• 123-76-2 levulinic acid 
• 26629-21-0 2,3-dihydro-1H-1-methylcyclopenta(b)quinoxaline 
• 74285-41-9 2-Benzyloxy-3-methyl-2-cyclopentenone 
• 105071-92-9 2-hydroxy-5-methyl-5-phenylcyclopent-2-en-1-one 
• 105071-91-8 2-hydroxy-5-methyl-3,5-diphenylcyclopent-2-en-1-one 
• 14189-85-6 2-methoxy-3-methylcyclopent-2-en-1-one 
• 51238-62-1 2-methoxy-5-methyl-cyclopent-2-enone 
• 1120-72-5 2-Methylcyclopentanone 
• 815575-39-4 3-bromo-4-methylbenzene-1,2-diol 
• 214557-51-4 7-methyl-1,4-dioxaspiro[4.4]nonan-6-one 
• 1196-22-1 2-methyl-5-oxocyclopent-1-en-1-yl acetate 
• 22058-99-7 2-hydroxy-2-methylpentanedioic acid 

Relevant articles and documents

Synthesis of 2-hydroxy-3-methyl-2-cyclo-pentenone, corylone, from 2-ketoglutaric acid

Treatment of 2-ketoglutaric acid with diazomethane gave 2-(methoxycarbonyl)-oxiranepropanoic acid methyl ester (2) which lead to 2-hydroxy-2-methyl-glutaric acid dimethyl ester (3) by catalytic hydrogenation, which was further processed to the title compound.

Synthetic method of methyl cyclopentenolone

The invention relates to a preparation method of methyl cyclopentenolone, which comprises the following steps: (1) controlling the pH value and temperature of a reaction system, and reacting a dimethylamine hydrochloride, a formaldehyde aqueous solution and 2-methyl furan to generate N, N-dimethyl-5-methyl furfuryl amine; (2) when it is monitored that the content of the 2-methyl furan is not reduced any more, adjusting the pH value of the reaction solution to be less than 1 by using an acid solution, and reacting to obtain a product 1-dimethyl amino-2, 5-hexanedione; and (3) adjusting the pH value of the reaction solution to 12-13 by using an alkali, reacting, extracting the reaction solution, concentrating to recover the solvent, and rectifying to obtain a product 2-(dimethylamino)-3-methyl-2-cyclopentene-1-one; and (4) mixing 2-(dimethylamino)-3-methyl-2-cyclopentene-1-one with hydrochloric acid, reacting, hydrolyzing, crystallizing and purifying to obtain methyl cyclopentenolone, and concentrating and recycling a reaction mother liquor Compared with the prior art, the method has the advantages that remote and automatic operation is facilitated, wastewater treatment is reduced, and the raw material dimethylamine hydrochloride can be reused.

Green synthesis method of methyl cyclopentenolone

The invention relates to a green synthesis method of methyl cyclopentenolone, and belongs to the field of organic synthesis. The method comprises the following synthesis steps: A, carrying out Mannichreaction on 2-methyl furan serving as a raw material and piperidine hydrochloride to generate an aminated intermediate; B, adding a catalytic amount of sulfuric acid into the aminated intermediate for reflux reaction to obtain a hydrolysate; and C, adding the hydrolysate into methylbenzene, neutralizing to be neutral by using sodium hydroxide, adding piperidine and pyridine, refluxing and separating water until no water is separated out, and rectifying to obtain a cyclized product; and D, putting the cyclized product into an acetic acid-hydrochloric acid solution for reflux reaction, cooling,removing piperidine hydrochloride, removing acetic acid from the filtrate, adding water, and crystallizing to obtain methyl cyclopentenolone. According to the method, the generation of wastewater andwaste salt is greatly reduced, the generated piperidine hydrochloride can be recycled and reused, and the method is a green synthetic method for synthesizing methyl cyclopentenolone.

Convenient and easy access to 2-hydroxycyclopent-2-enones from acylcyanohydrins

A convenient access to 2-hydroxycyclopentenones was designed from acylcyanohydrins, by using titanacyclopropane complexes as nucleophilic partners and an intramolecular aldol condensation in basic conditions. The development of a one-pot procedure allows a step- and atom-economic process, and the use of Grignard reagents other than ethylmagnesium bromide provided valuable 3,4-disubstituted 2-hydroxycyclopentenones. The utility of the hydroxy group was illustrated by further functionalization of the α-position using palladium-mediated cross-coupling reactions.

Cyclopentanone Derivatives from 5-Hydroxymethylfurfural via 1-Hydroxyhexane-2,5-dione as Intermediate

An efficient strategy for the conversion of biomass derived 5-hydroxymethylfurfural (HMF) into 2-hydroxy-3-methylcyclopent-2-enone (MCP) by an intramolecular aldol condensation of 1-hydroxyhexane-2,5-dione (HHD) has been developed. Further transformations of MCP towards the diol, enol acetate, levulinic acid and N-heterocyclic compounds are also reported.

Effect of Cp*Iridium(III) Complex and acid co-catalyst on conversion of furfural compounds to cyclopentanones or straight chain ketones

In this paper, Cp*Ir (III) Complex and acid co-catalyst system was developed. By using Cp*Ir and γ-Al2O3 (Lewis acid), 5-hydroxymethylfurfural (5-HMF) can be converted efficiently to 3-hydroxymethyl cyclopentanone (HCPN). Meanwhile, Cp*Ir and Br?nsted acid can promote conversion of 5-HMF to 1-Hydroxy-2,5-hexanedione (HHD). The effect of Lewis acid and Br?nsted acid on the hydrogenation of furan derivatives was studied. Mechanism of conversion of 5-HMF to HCPN was discussed in detail and mechanism proposed by our predecessors was revised. Instead of being an intermediate for the formation of HCPN, it is believed that, HHD is a product of another reaction pathway. HHD condensed via Aldol reaction to produce 3-methylcyclopenten-2-ol-1-one (MCP) instead of HCPN. Under the promotion of Lewis acid, 5-HMF firstly convert to the precursor of HHD. After that, the reaction is through 4 π-electrocyclic ring closure process and HCPN was formed ultimately. Furthermore, we found that our Cp*Ir and acid co-catalyst system is suitable for a variety of furfural compounds. By using Cp*Ir, Br?nsted acid can promote conversion of furfural compounds to straight chain ketones and Lewis acid can promote the rearrangement of furfural compounds to cyclopentanone derivatives.

Conversion of HMF to methyl cyclopentenolone using Pd/Nb2O5 and Ca-Al catalysts: Via a two-step procedure

The catalytic conversion of HMF to 2-hydroxy-3-methyl-2-cyclopenten-1-one (MCP), which is a valuable edible essence that has traditionally been obtained from adipic acid, was achieved with an isolated yield of 58%. This procedure comprised two steps: the hydrogenation of 5-hydroxymethylfurfural (HMF) to 1-hydroxy-2,5-hexanedione (HHD) in water on Pd/Nb2O5 catalysts and then the isomerization of HHD to MCP in the presence of a base. The Nb2O5 supports, which were acidic, were characterized by FTIR, XRD and NH3-TPD. The supported Pd/Nb2O5 catalysts, in which Pd was highly dispersed, were synthesized employing cyclohexene as a reductant and were characterized by XRD, TEM, ICP-AES, XPS, EDX and CO pulse chemisorption. The high conversion of HMF was attributed to the high dispersion of Pd, and the acidity of the supports led to high selectivity for HHD. The conversion of HHD to MCP was an intramolecular aldol condensation reaction, and the protonic solvent favored this reaction. Ca-Al was proved to be an effective solid base for the conversion of HHD to MCP in water.

Method of preparing 2-hydroxy-3-methyl-2-cyclopentene-1-one from fructose

The invention discloses a method of preparing 2-hydroxy-3-methyl-2-cyclopentene-1-one with fructose as a raw material. The method includes the following steps: 1) under a hydrogen atmosphere, performing hydrodeoxygenation to the fructose on a Pd-based hydrogenation catalyst to generate 1-hydroxy-2,5-hexanedione; and 2) performing isomerization to the 1-hydroxy-2,5-hexanedione to prepare the 2-hydroxy-3-methyl-2-cyclopentene-1-one from fructose under an alkali condition. The method only includes two catalytic reactions, is simple in production process and is high in total yield. Water is employed as a solvent in the reactions without usage of any toxic and harmful reagents, so that the method is mild in reaction conditions and is green and environment-friendly. The method is high in yield and is less in side products. The product is convenient to separate and purify.

Heterogeneous platinum catalytic aerobic oxidation of cyclopentane-1,2- diols to cyclopentane-1,2-diones

A method for the aerobic oxidation of cyclopentane-1,2-diols to the corresponding diketones over a commercial heterogeneous Pt/C catalyst is described. Unsubstituted and 3- or 4-substituted cyclopentane-1,2-diols are oxidized to 1,2-dicarbonyl compounds in good yields under the reported optimized reaction conditions (atmospheric air, 1 mol % of catalyst, 1 equiv of LiOH, aqueous solvents and 60 °C temperature). The method is applicable for producing cyclopentane-1,2-diketones in a scalable manner.

Practical preparation of diosphenols by ring opening of α,β-epoxyketones catalyzed by silica gel supported acids

The mixed acid (H2SO4-HOAc) catalyzed ring opening of α,β-epoxyketone was the most used method for the preparation of diosphenols, but it seriously suffered from poor yields and tedious workup operations. By using silica gel supported mixed acid (H2SO 4-HOAc), a variety of α,β-epoxyketones were converted into the corresponding diosphenols in unprecedented high yields within a few minutes. Georg Thieme Verlag Stuttgart.