5870-63-3

Usage

Uses

Used in Food and Beverage Industry:
3-HYDROXY-2-METHYL-CYCLOPENT-2-ENONE is used as a flavoring substance for its aromatic properties, enhancing the taste and aroma of various food and beverage products.
Used in Fragrance and Perfume Industry:
3-HYDROXY-2-METHYL-CYCLOPENT-2-ENONE is used as a key ingredient in the production of fragrances and perfumes, contributing to their unique and appealing scents.
Used in Cosmetics Industry:
3-HYDROXY-2-METHYL-CYCLOPENT-2-ENONE is utilized in the formulation of cosmetics due to its aromatic properties, adding a pleasant scent and enhancing the sensory experience of the products.
Used in Pharmaceutical Industry:
3-HYDROXY-2-METHYL-CYCLOPENT-2-ENONE has potential applications in the pharmaceutical field, serving as an intermediate for the synthesis of other organic compounds with therapeutic properties.
Used in Chemical Research:
3-HYDROXY-2-METHYL-CYCLOPENT-2-ENONE is employed in chemical research for its unique chemical structure and potential to contribute to the development of new compounds and materials.

Synthetic route

2-methylcyclopentane-1,3-dione ethylene glycol monoacetal (54972-03-1) → 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3)

Conditions	Yield
With hydrogenchloride In tetrahydrofuran; water for 10h;	71%

2-(1-ethoxy-ethyl)-2-hydroxy-cyclobutanone → 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3)

Conditions	Yield
With Amberlyst 15; trifluoroacetic acid for 10h; Heating;	0.088 g

cyclopent-2-enone (930-30-3) → 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3)

Conditions

Yield

Multi-step reaction with 5 steps 1.1: N,N,N,N,N,N-hexamethylphosphoric triamide; methyllithium / diethyl ether / 0.5 h / 0 °C / Inert atmosphere 1.2: 1 h / -78 °C / Inert atmosphere 1.3: 3 h / -78 - 20 °C / Inert atmosphere 2.1: toluene-4-sulfonic acid / benzene / 6 h / Reflux; Dean-Stark 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.33 h / Inert atmosphere 3.2: 20 h 4.1: tetrapropylammonium perruthennate; 4-methylmorpholine N-oxide / dichloromethane / 0.5 h / Molecular sieve; Inert atmosphere 5.1: hydrogenchloride / tetrahydrofuran; water / 10 h View Scheme

trans-2-methyl-3-(pentamethyldisilan-1-yl)cyclopentan-1-one → 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: toluene-4-sulfonic acid / benzene / 6 h / Reflux; Dean-Stark 2.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.33 h / Inert atmosphere 2.2: 20 h 3.1: tetrapropylammonium perruthennate; 4-methylmorpholine N-oxide / dichloromethane / 0.5 h / Molecular sieve; Inert atmosphere 4.1: hydrogenchloride / tetrahydrofuran; water / 10 h View Scheme

1,1,1,2,2-pentamethyl-2-[trans-6-methyl-1,4-dioxaspiro[4,4]-nonan-7-yl]disilane → 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.33 h / Inert atmosphere 1.2: 20 h 2.1: tetrapropylammonium perruthennate; 4-methylmorpholine N-oxide / dichloromethane / 0.5 h / Molecular sieve; Inert atmosphere 3.1: hydrogenchloride / tetrahydrofuran; water / 10 h View Scheme

trans-6-methyl-1,4-dioxaspiro[4.4]nonan-7-ol → 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: tetrapropylammonium perruthennate; 4-methylmorpholine N-oxide / dichloromethane / 0.5 h / Molecular sieve; Inert atmosphere 2: hydrogenchloride / tetrahydrofuran; water / 10 h View Scheme

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + orthoformic acid triethyl ester (122-51-0) → 2-Methylcyclopent-1,3-dione monoethyl enol ether (25112-86-1)

Conditions	Yield
With sulfuric acid In ethanol	98%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-chloro-2-methylcyclopent-2-en-1-one (35173-23-0)

Conditions	Yield
With diethyl(trichloromethyl)phosphine In dichloromethane for 12h; Ambient temperature;	92%
With tetrachloromethane; triphenylphosphine
With oxalyl dichloride In N,N-dimethyl-formamide

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 4,5-dioxohexanoic acid (89533-82-4)

Conditions	Yield
With oxygen; copper(II) perchlorate In acetonitrile for 12h; Ambient temperature;	92%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + benzylamine (100-46-9) → 3-(benzylamino)-2-methylcyclopent-2-en-1-one (134622-65-4)

Conditions	Yield
With toluene-4-sulfonic acid In toluene for 10h; Heating;	92%
With toluene-4-sulfonic acid In toluene Heating;	92%

N-(phenylthio)succinimide (14204-24-1) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 2-methyl-2-(phenylthio)-1,3-cyclopentanedione (72302-65-9)

Conditions	Yield
With triethylamine In benzene for 2h; Heating;	90%

hexan-1-amine (111-26-2) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-Hexylamino-2-methyl-cyclopent-2-enone (183674-19-3)

Conditions	Yield
With toluene-4-sulfonic acid In toluene Heating;	90%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + 1-aminopent-3-yne (91640-80-1) → C11H15NO

Conditions	Yield
With toluene-4-sulfonic acid In diethyl ether; toluene at 120℃; for 20h; Dean-Stark;	87%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-iodo-2-methyl-2-cyclopentenone (56778-49-5)

Conditions	Yield
With iodine; triethylamine; triphenylphosphine In acetonitrile for 12h; Reflux; Inert atmosphere;	87%

methanol (67-56-1) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-methoxy-2-methylcyclopent-2-enone (3883-56-5) + 2-methyl-3-phenylsulfanyl-cyclopent-2-enone (82909-44-2)

Conditions	Yield
With camphor-10-sulfonic acid; thiophenol at 20℃; for 96h;	A 10% B 78%

pent-3-yn-1-ol (10229-10-4) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → C11H14O2

Conditions	Yield
With toluene-4-sulfonic acid In toluene at 130℃; for 20h; Dean-Stark;	77%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + thiophenol (108-98-5) → 2-methyl-3-phenylsulfanyl-cyclopent-2-enone (82909-44-2)

Conditions	Yield
With camphor-10-sulfonic acid In methanol at 50℃; for 21h;	76%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + methyl vinyl ketone (78-94-4) → 2-methyl-2-(3-oxobutyl)-1,3-cyclopentanedione (25112-78-1)

Conditions	Yield
at 150℃; for 3h;	65%
With acetic acid In water at 70℃; Darkness; Inert atmosphere;

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + δ-Phenylselenenylbutanol (117901-60-7) → 3-(4-phenylselenobutanoxy)-2-methylcyclopent-2-en-1-one (118824-28-5)

Conditions	Yield
With toluene-4-sulfonic acid In benzene for 9h; Heating;	53%
With toluene-4-sulfonic acid In benzene Dean-Stark conditions;	53%

pyrrolidine (123-75-1) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 2-methyl-3-(1-pyrrolidinyl)-2-cyclopenten-1-one (3335-02-2)

Conditions	Yield
With acetic acid In ethanol for 4h; Heating;	5%

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-Bromo-2-methylcyclopent-2-en-1-one (56671-87-5)

Conditions	Yield
With carbon tetrabromide; triphenylphosphine In chloroform

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + ethyl 2-bromomethyl-2-propenoate (17435-72-2) → 2-(1-Methyl-2,5-dioxo-cyclopentylmethyl)-acrylic acid ethyl ester (53696-39-2)

Conditions	Yield
With potassium carbonate In acetone

methanol (67-56-1) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-methoxy-2-methylcyclopent-2-enone (3883-56-5)

Conditions	Yield
With toluene-4-sulfonic acid In benzene

ethanol (64-17-5) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 2-Methylcyclopent-1,3-dione monoethyl enol ether (25112-86-1)

Conditions	Yield
With toluene-4-sulfonic acid In benzene

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + (3-bromopropyl)(phenyl)selane (118824-31-0) → 3-(3-phenylselenopropanoxy)-2-methylcyclopent-2-en-1-one (118824-29-6)

Conditions	Yield
With sodium hydride 1) DMF, 0 deg C - room temperature, 20 min, 2) 70 deg C, 3 h; Yield given. Multistep reaction;
With sodium hydride DMF; Yield given. Multistep reaction;

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + 1-bromo-4-phenylselenobutane (118824-39-8) → 3-(4-phenylselenobutanoxy)-2-methylcyclopent-2-en-1-one (118824-28-5)

Conditions	Yield
With sodium hydride 1) DMF, 0 deg C - room temperature, 20 min, 2) 70 deg C, 4 h; Yield given. Multistep reaction;
With sodium hydride DMF; Yield given. Multistep reaction;

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + ethyl iodide (75-03-6) → 2-Ethyl-2-methyl-1,3-cyclopentanedione (25112-87-2)

Conditions	Yield
With potassium hydroxide

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + methyl iodide (74-88-4) → 2,2-dimethylcyclopentane-1,3-dione (3883-58-7)

Conditions	Yield
With potassium hydroxide

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + 2-(chloromethyl)-6-methoxy-4-(1-methylethyl)-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (142577-03-5) → 4-Isopropyl-6-methoxy-2-(2-methyl-3-oxo-cyclopent-1-enyloxymethyl)-1,1-dioxo-1,2-dihydro-1λ6-benzo[d]isothiazol-3-one

Conditions	Yield
With sodium hydride 1.) DMF, RT, 30 min, 2.) DMF, RT, 144 h; Yield given. Multistep reaction;

diazomethane (186581-53-3, 908094-01-9) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 3-methoxy-2-methylcyclopent-2-enone (3883-56-5)

Conditions	Yield
In tetrahydrofuran; diethyl ether

3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) + aniline (62-53-3) → 4-oxo-5-(phenyl-hydrazono)-hexanoic acid

Conditions	Yield
With hydrogenchloride; sodium acetate; sodium nitrite 1) H2O, 0 deg C, 15 min, 2) H2O; Yield given. Multistep reaction;

Nonafluorobutanesulfonyl fluoride (375-72-4) + 3-hydroxy-2-methyl-2-cyclopenten-1-one (5870-63-3) → 2-methyl-3-(perfluoro-1-butanesulfonyloxy)-2-cyclopenten-1-one

Conditions	Yield
With sodium hydride 1.) DMF, room temperature (4 h), 45 deg C (45 min), 2.) DMF, room temperature, 3.5 h; Yield given; Multistep reaction;

Upstream product

• 930-30-3 cyclopent-2-enone 
• 54972-03-1 2-methylcyclopentane-1,3-dione ethylene glycol monoacetal 

Downstream Products

• 3883-56-5 3-methoxy-2-methylcyclopent-2-enone 
• 72302-65-9 2-methyl-2-(phenylthio)-1,3-cyclopentanedione 
• 25112-86-1 2-Methylcyclopent-1,3-dione monoethyl enol ether 
• 118824-28-5 3-(4-phenylselenobutanoxy)-2-methylcyclopent-2-en-1-one 
• 118824-29-6 3-(3-phenylselenopropanoxy)-2-methylcyclopent-2-en-1-one 
• 25112-78-1 2-methyl-2-(3-oxobutyl)-1,3-cyclopentanedione 
• 3883-58-7 2,2-dimethylcyclopentane-1,3-dione 
• 134622-65-4 3-(benzylamino)-2-methylcyclopent-2-en-1-one 
• 82909-44-2 2-methyl-3-phenylsulfanyl-cyclopent-2-enone 
• 54158-61-1 2-methyl-3-(4-methylphenyl)-2-cyclopentenone 
• 4608-44-0 2,3-dimethyl-3-(p-tolyl)cyclopentan-1-one 
• 33879-04-8 (+)-(3aS,7aS)-2,3,3a,4,7,7a-hexahydro-3a-hydroxy-7a-methyl-1H-indene-1,5(6H)-dione 
• 17553-86-5 (S)-Halos-Parish ketone 
• 1909-79-1 2-methyl-2-cyclopenten-1-one-3-carboxylic acid 

Relevant academic research and scientific papers

Conversion of cycloalk-2-enones into 2-methylcycloalkane-1,3-diones - Assessment of various Tamao-Fleming procedures and mechanistic insight into the use of the Me3SiMe2Si unit

Conjugate addition of Me3SiMe2SiLi to cycloalk-2-en-1-ones, ketalization, Tamao-Fleming oxidation (Bu4NF, then H2O2, KHCO3), TPAP oxidation and acid hydrolysis generates 2-methyl cycloalkane-1,3-diones. Ketalization is needed in order to prevent addition of Me3Si- to the carbonyl. The pentamethyldisilanyl group has advantages over other silicon units that are used in Tamao-Fleming procedures.

Reactions of 1,2-bis(trimethylsilyloxy)cycloalkenes with the diethyl acetals of aldehydes

Lewis acid-mediated reactions of 1,2-bis(trimethylsilyloxy)-cyclobutene with acetals derived from a variety of aldehydes, followed by treatment with Amberlyst 15 resin in TFA, yielded 1,3-cyclopentanedione products, but reactions with 3,3-dimethyl-1,2-bis(trimethylsilyloxy)cyclobutene led to 1,2-cyclopentanediones. Reactions of 1,2-bis(trimethylsilyloxy)-cyclopentene gave intermediates that did not undergo skeletal rearrangement with Amberlyst 15 resin in TFA.