3- methyl-2-cyclopenten-l-one

Cyclopentanes, synthesis, 66, 10 CYCLOPEKTANONE SYNTHESIS, 66, 87, 92, 93 Cyclopentanone, 2-carbomethoxy-3-vinyl, 66, 56 Cyclopentanone, 2-ethenyl-2-methyl (88729-76-4), 66, 94 2-CYCLOPENTEN-l-ONE, 3-METHYL-2-PENTYL-, 65, 26 Cyclopropane, l-trimethy1s1lyloxy-1-ethoxy-, 56, 44 Cyclopropanecarboxylic acid chloride, 66, 176... 

METHYL-2-PEtfTYL-2-CYCLOPEKTEN-l -ONE 2-CYCLOPENTEN-l -ONE, 3-METHYL-2-PENTYL- (1128-08-1), 65, 26... 

Methyl-2-pentyl-2-cyclopenten-l-one 2-Cyclopenten-l-one, 3-methyl-2-pentyl - (8,9) (1128-08-1)... 

Stetter H, Kuhhnann H, Haese W (1987) The Stetter reaction 3-methyl-2-pentyl-2-cyclo-penten-l-one (dihydrojasmone) (2-cyclopenten-l-one, 3-methyl-2-pentyl-). Org Synth 65 26-31 Stetter H, Kuhhnann H (1991) The catalyzed nucleophilic addition of aldehydes to electrophilic double bonds. Org React 40 407 96... 

D.62) 2-Cyclopenten-l-one, 3-methyl-, 3-methylcydopent-l-en-2-one, 1-methyl-l-cyclopenten-3-one 12758-18-1] FEMA 3435... 

D.74) 2-Cyclopenten-l-one, 3-ethyl-2-hydroxy-4-methyl-, 3-ethyl-2-hydroxy-4-methylcyclopent-2-en-l-one [42348-12-9] FEMA 3453 1,2-cyclopentanedione, 3-ethyl-4-methyl-, 3-ethyl-4-methylcyclopentane-1,2-dione... 

Cyclohexen-l-one, 3-methyl-2-(2-pro-penyl)- [17605-08-21,55 Cyclopentene [142-29-0], 34 Cyclopropanecarboxylic acid [1759-53-1], 70... 

D.76) 2-Cyclopenten-l-one, 5-ethyl-2-hydroxy-3-methyl-, 5-ethyl-2-hydroxy-5-methylcydopent-2-en-l-one [53263-58-4] FEMA 3454 (tautomeric form of D.75)... 

D.77) 2-Cyclopenten-l-one, 4-ethyl-2-hydroxy-3-methyl-, 4-ethyl-2-hydroxy-3-methylcydopent-2-en-I-one [71387-71-8] 1,2-cyclopentanedione, 4-ethyl-3-methyl-, 4-ethyl-3-methylcyclopentane-l,2-dione... 

The authors chose pyruvic acid as their model compound this C3 molecule plays a central role in the metabolism of living cells. It was recently synthesized for the first time under hydrothermal conditions (Cody et al., 2000). Hazen and Deamer carried out their experiments at pressures and temperatures similar to those in hydrothermal systems (but not chosen to simulate such systems). The non-enzymatic reactions, which took place in relatively concentrated aqueous solutions, were intended to identify the subsequent self-selection and self-organisation potential of prebiotic molecular species. A considerable series of complex organic molecules was tentatively identified, such as methoxy- or methyl-substituted methyl benzoates or 2, 3, 4-trimethyl-2-cyclopenten-l-one, to name only a few. In particular, polymerisation products of pyruvic acid, and products of consecutive reactions such as decarboxylation and cycloaddition, were observed the expected tar fraction was not found, but water-soluble components were found as well as a chloroform-soluble fraction. The latter showed similarities to chloroform-soluble compounds from the Murchison carbonaceous chondrite (Hazen and Deamer, 2007). 

Of the four possible optical isomers, the (+)-( I )-cw-isomer possesses the most characteristic jasmin odor. Methyl dihydrojasmonate is prepared by Michael addition of malonic acid esters to 2-pentyl-2-cyclopenten-l-one, followed by hydrolysis and decarboxylation of the resulting (2-pentyl-3-oxocyclopentyl) malonate, and esterification of the (2-pentyl-3-oxocyclopentyl)acetic acid [136]. 

SYNS (+)-ALLELRETHONYL (+)-cis,trans-CHRYS-ANTHEMATE d-ALLETHRIN d-trans ALLE-THRIN ALLETHRIN 1 ALLEVIATE ALLYL CINERIN ALLYL HOMOLOG of CINERIN I d,l-2-ALLYL-4-HYDROXY-3-METHYL-2-CYCLOPENTEN-l-ONE-d,l-CHRYSANTHEMUM MONOCARBOXYLATE 3-ALLYL-4-KETO-2-METHYLCYCLOPENTENYL CHRYSAN-THEMUMMONOCARBOXYLATE 3-ALLYL-2-METHYL-4-OXO-2-CYCLOPENTEN-1-YL... 

CYCLOPENTENYL-4-HYDROXY-3-METHYL-2-CYCLOPENTEN-l-ONE CHRYSANTHEMATE see POOOOO... 

Acetoxy-2- (2-butenyl) - 5-carbethoxy - 3 -methyl - 2 - cyclopenten-l-one covered -with coned, aq. NH3, allowed to stand for 3 days with frequent shaking —> 2-(2-butenyl)-5-carbamyl-5-hydroxy-2-eyclopenten-l-one (Y 80%) boiled 1 hr. with 10% H2S04 2-(2-butenyl)-5-hydroxy-... 

Met A, hydrolysis product of allethrin dihydroxy acid + CCPCA 2-cyclopenten-l-one, 2-(2,3-dihydroxypropyl)-4-hydroxy-3-methyl-... 

A mixture of 2-methyl-3,5,5-triethoxy-2-cyclopenten-l-one and allyl bromide in dry ether added dropwise to stirred suspension of Mg in dry ether, refluxed 10 hrs., and acidified with cold 0.1 N H2SO4 2-allyl-3-methyl-2-cyclopentene-1,4-dione. Y 87%. F. e., also with retention of ketal groups by final treatment with water instead of sulfuric acid, s. M. Vandewalle and E. Madeleyn, Tetrahedron 26, 3551 (1970) s. a. Bl. Soc. diim. Belg. 79, 699 (1970) prepn. of highly reactive magnesium by reduction, also in situ, of Mg-salts, s. R. D. Rieke and P. M. Hudnall, Am. Soc. 94, 7178 (1972). 

Acetoxy-2-cyclopenten-l-one in r r/-butyl acetoacetate added drop wise to a stirred soln. of K-rerr-butoxide in f rr-butyl acetoacetate, and allowed to stand overnight di-r rf-butyl 3-hydroxy-3-methyl-5,9-dioxobicyclo[5.3.0]decan-2,6-di-carboxylate. Y 88%. V. Osterthun and E. Winterfeldt, B. 110, 146 (1977). 

One mole of isoprene reacted with one mole of acetoacetate by using a bidentate phosphine as ligand (56). Reaction of 2,3-dimethylbutadiene with acetoacetate was carried out by using PdCl2 in the presence of sodium phenoxide. When PPh3 was used, a 1 2 adduct was obtained. On the other hand, use of P-phenyl-l-phospha-3-methyl-3-cyclopentene (105) at 100°C caused the 1 1 addition to give 3-carbomethoxy-5,6-dimethyl-5-hepten-2-one (106), from which 5,6-dimethyl-5-hepten-2-one (107) was formed. This compound is the useful intermediate for a-irone synthesis (96). 

Hydroxy-3-methyl-2-cyclopenten-l-one, m223 l,3-Hydroxy-2-methyl-2-propylamine, a226... 

A plausible mechanism involves the reaction of the dihydride precursor with t-butylethylene to the 14-e complex [Ir(C6H3-2,6 CH2P-f-Bu2 2)]> which undergoes the oxidative-addition reaction of the alcohol to afford a hydride alkoxide complex. Further /i-hydride ehmination gives the alde-hyde/ketone and regenerates the dihydride active species [55]. In the particular case of 2,5-hexanediol as the substrate, the product is the cycHc ketone 3-methyl-2-cyclopenten-l-one. The formation of this ketone involves the oxidation of both OH groups to 2,5-hexanedione followed by an internal aldol reaction and further oxidation as in the final step of a Robinson annotation reaction [56]. 

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