80963-36-6

Basic information

• Product Name: 2-BROMO-3-METHYL-2-CYCLOPENTEN-1-ONE
• Synonyms: 2-BROMO-3-METHYL-2-CYCLOPENTEN-1-ONE;2-BROMO-3-METHYL-2-CYCLOPENTEN-1-ONE, 98;2-Bromo-3-methyl-2-cyclopenten-1-one 98%;2-Bromo-3-methylcyclopent-2-enone
• CAS NO: 80963-36-6
• Molecular Formula: C₆H₇BrO
• Molecular Weight: 175.02
• Product Categories: C3 to C6;Carbonyl Compounds;Ketones;Building Blocks;C3 to C6;Carbonyl Compounds;Chemical Synthesis;Organic Building Blocks
• Mol File: 80963-36-6.mol

Chemical Properties

• Melting Point: 53-56 °C(lit.)
• Boiling Point: 225.7°C at 760 mmHg
• Flash Point: >230 °F
• Appearance: /
• Density: 1.607g/cm³
• Vapor Pressure: 0.085mmHg at 25°C
• Refractive Index: 1.561
• CAS DataBase Reference: 2-BROMO-3-METHYL-2-CYCLOPENTEN-1-ONE(CAS DataBase Reference)
• NIST Chemistry Reference: 2-BROMO-3-METHYL-2-CYCLOPENTEN-1-ONE(80963-36-6)
• EPA Substance Registry System: 2-BROMO-3-METHYL-2-CYCLOPENTEN-1-ONE(80963-36-6)

Safety Data

• WGK Germany: 3
• Hazardous Substances Data: 80963-36-6(Hazardous Substances Data)

Usage

InChI:InChI=1/C6H7BrO/c1-4-2-3-5(8)6(4)7/h2-3H2,1H3

Upstream product

• 2758-18-1 3-Methyl-2-cyclopenten-1-one 
• 67-56-1 methanol 
• 70156-97-7 6-bromo-7-methyl-1,4-dioxaspiro<4.4>non-6-ene 
• 82222-80-8 3-methyl-3-((4-methylphenyl)sulfonyl)cyclopentanone 

Downstream Products

• 1159426-49-9 2-(1-(3,5-dimethoxyphenyl)ethyl)-3-methylcyclopent-2-enone 
• 1159426-48-8 2-(3,5-dimethoxyphenethyl)-3-methylcyclopent-2-enone 
• 1319079-39-4 (S)-8-(benzyloxy)-6-bromo-7-methyl-1,4-dioxaspiro[4.4]non-6-ene 
• 1319079-25-8 (1S,4S)-4-(benzyloxy)-2-bromo-3-methyl-1-(prop-1-en-2-yl)cyclopent-2-enol 
• 1319079-18-9 (S)-4-(benzyloxy)-2-bromo-3-methylcyclopent-2-enone 
• 1319079-41-8 4-(benzyloxy)-2-bromo-1-isopropyl-3-methylcyclopent-2-enol 
• 1319079-24-7 (1S,4S)-4-(benzyloxy)-2-bromo-1-isopropyl-3-methylcyclopent-2-enol 
• 628732-00-3 C₁₅H₁₅NO 
• 628732-01-4 [2-(4-fluoro-phenyl)-3-methyl-cyclopent-2-enyl]-acetaldehyde 
• 628731-99-7 C₁₃H₁₃NO 
• 628731-42-0 4-(2-ethyl-3-methyl-cyclopent-2-enylmethyl)-1,3-dihydro-imidazol-2-one 
• 108060-98-6 (R)-1-[(1R,3R)-3-(tert-Butyl-dimethyl-silanyloxy)-1-methyl-2-methylene-cyclopentyl]-2-oxo-cyclohexanecarbonitrile 
• 108060-98-6 (S)-1-[(1R,3R)-3-(tert-Butyl-dimethyl-silanyloxy)-1-methyl-2-methylene-cyclopentyl]-2-oxo-cyclohexanecarbonitrile 
• 108060-97-5 2-[5-(tert-Butyl-dimethyl-silanyloxy)-2-methyl-cyclopent-1-enylmethoxy]-cyclohex-1-enecarbonitrile 

Relevant articles and documents

Synthesis of enantiomerically pure (R)- and (S)-3-methyl-2-cyclopenten-1-ol

(R)- and (S)-3-methyl-2-cyclopenten-1-ol are prepared from 3-methyl-2-cyclopentenone with high enantiomeric purity (> 95%) through a 4-step sequence involving the enantioselective enzymatic esterification of 2-bromo-3-methyl-2-cyclopenten-1-ol with lipase

2-Lithio-3-methoxy-1,3-dimethylcyclopentene: A synthetic equivalent of 2-lithio-1,3-dimethylcyclopentadiene and useful synthon for 6-alkyl-1,4- dimethylfulvenes and ansa-metallocene complexes

2-Bromo-3-methoxy-1,3-dimethylcyclopentene (3). is synthesized in 85% yield in 80 g scale by 1,2-addition of MeLi to 2-bromo-3-methyl-2-cyclopenten-1-one and subsequent in situ treatment of MeI. Addition of n-BuLi to the bromo-compound 3 in Et2O affords 2-lithio-3-methoxy-1,3- dimethylcyclopentene (1). Successive addition of RCHO [R = CH3, (CH2)2CH3, CH(CH3)2, C(CH3)3, H] and MeI to the lithium compound and aqueous acidic work-up provide cyclopentadiene compounds, 2-[CHR(OMe)]-1,3-Me 2C5H3 in 60-84% yields. Treatment of the cyclopentadienes with NaH or KH in pentane affords 1,4,6-trimethylfulvene, 6-n-propyl-1,4-dimethylfulvene, 6-isopropyl-1,4-dimethylfulvene, 6-tert-butyl-1,4-dimethylfulvene and 1,4-dimethylfulvenein 67-83% yields. Ligand for an ansa-metallocene complex, CH2C(1,3-Me2Cp) 2ZrCl2, can be shortly afforded in 64% yield by reacting the lithium compound 1 with the newly synthesized 1,4-dimethylfulvene.

Copper-Catalyzed Enantioselective 1,2-Reduction of Cycloalkenones

We report an asymmetric 1,2-reduction of cyclic α,β-unsaturated ketones to access various enantiomerically enriched cyclic allylic alcohols under mild conditions, catalyzed by in situ generated copper hydride ligated with (R)-DTBM-C3*-TunePhos. α-Brominated cycloalkenones were reduced with excellent enantioselectivities of up to 98% ee, while substrates that were without α-substituents were reduced chemoselectively, with moderate enantioselectivities.

Sequential O-Arylation/Lanthanide(III)-Catalyzed [3,3]-Sigmatropic Rearrangement of Bromo-Substituted Allylic Alcohols

Lanthanide(III)-catalyzed aryl-Claisen rearrangement of substrates bearing halo-substituted allyl groups, specifically 2-bromoallyl aryl ethers, afford ortho -2-bromoallylphenols. Aryl ether substrates were synthesized from brominated allylic alcohols via Mitsunobu reaction, Cu(II)-catalyzed arylation using potassium aryltrifluoroborate salts, or S N Ar reaction. Aryl-Claisen rearrangements proceeded in moderate to excellent yields using Eu(III) catalysis. The alkenylbromide functionality remains intact, illustrating the compatibility of synthetically important alkenylhalides during C-O/C-C σ-bond migration processes. Subsequent derivatization of the ortho -2-bromoallylphenol products through O-alkylation or C-arylation/alkenylation via Suzuki-Miyaura cross-coupling demonstrate the potential to access densely-functionalized molecules.

SYNTHESIS OF ENT-PROGESTERONE AND INTERMEDIATES THEREOF

The present invention relates to the synthesis of ent-progesterone and intermediates thereof.

SYNTHESIS OF ENT-PROGESTERONE AND INTERMEDIATES THEREOF

The present invention relates to the synthesis of ent-progesterone and intermediates thereof.

Enantioselective synthesis of the C10-C20 fragment of fusicoccin A

A synthesis of the fully protected C-ring fragment of the tricyclic diterpene fusicoccin A is reported. The desired cyclopentenyl halides 5a,b are obtained in a total of nine steps. Key transformations of the synthesis sequence are a nonconventional Cr-catalyzed allylic oxidation of a protected intermediate cylcopentenone, a diastereoselective addition of a propenyl Grignard/CeCl3 reagent to the unmasked cyclopentenone, and an asymmetric hydroboration of the isopropenyl substituent. The protected and suitably functionalized C-ring fragment paves the way to explore further the total synthesis of fusicoccin A.

Highly enantioselective and regioselective carbonyl reduction of cyclic α,β-unsaturated ketones using TarB-N02 and sodium borohydride

Asymmetric 1,2-reduction of α,β-unsaturated ketones using TarB-NO2 and NaBH4 Is reported. Simple cycloalkenones give products In low enantiomeric excess. However, cycloalkenones with a-substituents, such as halides, alkyl, and aryl, have been enantioselectively reduced with this system to yield chiral allylic alcohols In enantiomeric excess up to 99%. The starting materials for TarB-N02 are inexpensive, and the boronlc acid can be easily recovered In high yield by a simple acid extraction.

A remarkably simple one-step procedure for the preparation of α-bromo-α,β-unsaturated carbonyl compounds

An easy and convenient one-step procedure for the conversion of α,β-unsaturated carbonyl compounds into their corresponding bromo-enones using NBS-Et3N·3HBr in the presence of potassium carbonate in dichloromethane at 0°C to room temperature under very mild conditions in high yields and significantly shorter times, is reported. Georg Thieme Verlag Stuttgart.

Halogenation of carbonyl compounds by an ionic liquid, [AcMIm]X, and Ceric Ammonium Nitrate (CAN)

An ionic liquid, acetylmethylimidazolium halide ([AcMIm]X), in combination with ceric ammonium nitrate promotes halogenations of a wide variety of ketones and 1,3-keto esters at the ?-position. The ionic liquid acts here as reagent as well as reaction medium, and thus the reaction does not require any organic solvent or conventional halogenating agent. The reaction is completely arrested when the radical quencher TEMPO is used. A plausible radical mechanism is also suggested. CSIRO 2007.