1121-05-7Relevant articles and documents
Deno,N.C.,Houser,J.J.
, p. 1741 - 1743 (1964)
Pheromone synthesis. Part 262: Determination of the absolute configuration of the female sex pheromone [(1S,2S)-(?)-(1,2-dimethyl-3-methylenecyclopentyl) acetaldehyde] of the pineapple mealybug (Dysmicoccus brevipes) by synthesis coupled with X-ray analysis
Mori, Kenji,Tabata, Jun
, p. 6530 - 6541 (2017)
The enantiomers of (anti-1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde, one of which is the female sex pheromone of the pineapple mealybug (Dysmicoccus brevipes), were synthesized. Chirality was introduced by means of lipase-catalyzed asymmetric acetylation of (±)-2,3-dimethyl-2-cyclopenten-l-ol. X-ray analysis of (?)-camphanate ester of (1S,2S)-(?)-2-(1,2-dimethyl-3-methylenecyclopentyl)ethanol confirmed its (1S,2S)-absolute configuration. The natural pheromone was identified with the (1S,2S)-aldehyde by comparing the specific rotation, enantioselective GC retention time and pheromone activity.
A convenient synthesis method for methylenomycin B and its application to methylenomycin A
Tonari Machiya Ichimoto,Ueda
, p. 295 - 300 (1981)
-
McMurry,Melton
, p. 5309 (1971)
-
Casey,C.P. et al.
, p. 2071 - 2074 (1973)
-
-
Agosta,W.C.,Smith,A.B.
, p. 5513 - 5520 (1971)
-
Cyclopentenones from the Acid-induced Ring Expansion of 1-Alkenylcyclopropanol Derivatives
Barnier, Jean-Pierre,Karkour, Belkacem,Salauen, Jacques
, p. 1270 - 1272 (1985)
1-Alkenylcyclopropanols (4a,b) and (5a,b) underwent acid-induced ring expansion into cyclopentenones (7), via 2-alkenylcyclobutanones (6); the 2-methylcyclopropanols (15a,b) are also synthesised using the same method.
-
Naryshkina,T.I.,Bel'skii,I.F.
, (1965)
-
Polymer-mediated reactions. A Nazarov-like cyclization
Pavlik, Christopher,Morton, Martha D.,Invernale, Michael A.,Berghorn, Ian D.,Sotzing, Gregory A.,Smith, Michael B.
, p. 2195 - 2199 (2011)
The polymer PEDOT+ mediates a Nazarov-like cyclization of dienones, in an heterogeneous system and in hydrocarbon solvents. The polymer-mediated reactions show clear differences in product formation when compared to the same reaction with tosic acid, or when compared to reports in the literature. Comparable or improved yields are observed, as well as the ability to give a -Nazarov product in cases where treatment with acid fails to give cyclization, or leads to an undesirable rearrangement. In addition, the ability to recycle the polymer makes this a potentially useful protocol for an important organic chemical reaction. Georg Thieme Verlag Stuttgart · New York.
A new synthetic route to methylenomycin B via Rhodium(II)-mediated decomposition of α,β-unsaturated α'-diazoketones
Ceccherelli,Curini,Marcotullio,Rosati
, p. 17 - 23 (1991)
A new synthesis of methylenomycin B, involving Rh(II)-catalyzed, intramolecular carbon-hydrogen insertion of diazoketone 2c, derived from 2,3-dimethyl-2-butenoic acid 2b, is reported.
Acyclic O- and N-substituted Pentadienyl Cations: Structural Characterisation, Cyclisation and Computational Results
Howell, James A. S.,O'Leary, Paula J.,Yates, Paul C.,Goldschmidt, Zeev,Gottlieb, Hugo E.,Hezroni-Langerman, Daphna
, p. 7231 - 7246 (1995)
A number of 1- and 3-hydroxy and 1-amino substituted acyclic pentadienyl cations have been characterised by NMR spectroscopy in situ at low temperature.Some of the 3-hydroxy cations undergo cyclisation to give 1-hydroxycyclopentenyl cations which on deprotonation give substituted cyclopentenones.
METHOD OF PRODUCING 2,3-DIMETHYL-2-CYCLOPENTENONE
-
Paragraph 0008; 0035-0040, (2020/04/09)
PROBLEM TO BE SOLVED: To provide a method of industrially producing 2,3-dimethyl-2-cyclopentenone. SOLUTION: In a first step, a compound represented by formula (1) and acetone are reacted in the presence of a base to obtain a compound represented by formula (2). Then, the compound represented by formula (2) is subjected to second, third and fourth steps to obtain a compound represented by formula (6), which is further reacted in the presence of an acid or base to produce 2,3-dimethyl-2-cyclopentenone represented by formula (7). SELECTED DRAWING: None COPYRIGHT: (C)2020,JPO&INPIT
Reaction routes in catalytic reforming of poly(3-hydroxybutyrate) into renewable hydrocarbon oil
Kang, Shimin,Yu, Jian
, p. 30005 - 30013 (2015/05/13)
Poly(3-hydroxybutyrate) or PHB is an energy storage material of microbial organisms and can be reformed into hydrocarbon oils rich with aromatic compounds. This work investigated the main reaction routes from PHB to the key intermediates and final hydrocarbons. The main sequential reactions under catalysis of phosphoric acid at moderate temperatures (200-230 °C) consist of: (1) decomposition of PHB into crotonic acid, a major monomeric intermediate, (2) deoxygenation of crotonic acid, and (3) combination of the deoxygenated molecules. The oxygen in PHB is removed as CO2 and H2O in stage (2), involving decarboxylation and ketonization of crotonic acid. The main aromatic compounds are formed in stage (3) from propylene and 2,3-dimethyl-2-cyclopenten-1-one as two key intermediates, the former from decarboxylation and the latter from ketonization of crotonic acid. The reaction routes reveal that the formation of aromatics is affected to a great extent by the concentrations of phosphoric acid and water in the reaction, which can be used to control the composition of hydrocarbon oil.
