2931-10-4

Upstream product

• 18776-90-4 (E)-hept-5-enoic acid 
• 1119-60-4 hept-6-enoic acid 
• 5682-73-5 2-isobutoxycyclopent-2-enone 
• 821-57-8 7-chloroheptanoic acid 
• 97197-09-6 Bis-(2-chloro-2-ethyl-cyclopentyl)-diazene N,N'-dioxide 
• 26343-69-1 (E)-2-ethylidenecyclopentanone 
• 86119-84-8 phosphoric acid 
• 930-30-3 cyclopent-2-enone 
• 2146-38-5 1-ethylcyclopentene 
• 64847-88-7 2-ethylcyclopentanone 
• 55999-04-7 hept-5t-enenitrile 
• 62614-70-4 trans-1-chlorohex-4-ene 
• 1462-96-0 1-ethylcyclopentanol 
• 3008-40-0 cyclopentane-1,2-dione 

Downstream Products

• 5941-92-4 (+/-)-13-ethyl-3-methoxy-14β-gona-1,3,5(10),8-tetraen-17-one 
• 848-07-7 (+/-)-13-ethyl-3-methoxygona-1,3,5⁽¹⁰⁾,8,14-pentaen-17-one 

Relevant academic research and scientific papers

METHODS OF PREPARING a,?-UNSATURATED OR a-HALO KETONES AND ALDEHYDES

Copper(II) bromide mediated oxidation of acylated enol and use of the reaction in the synthesis of α,β-unsaturated or α-bromo ketones or aldehydes are disclosed. The method provides an efficient and practical process for manufacturing dehydrohedione (DHH) and many other versatile α,β-unsaturated or α-bromo ketones or aldehydes in large scales to avoid using precious metal compounds.

α,β-Unsaturated ketones via copper(II) bromide mediated oxidation

A protocol for effecting a rapid Saegusa-type oxidation of enol acetates is reported. This new method relies on the in situ elimination of an α-bromo intermediate to generate α,β-unsaturated ketones using copper(II) bromide. The methodology developed was applied to a range of substrates including a cyclohexanone, which could be directly converted to the corresponding phenol derivative. A catalytic system in which a non-masked ketone was successfully oxidised using substoichiometric CuBr2 was also developed as a proof of principle.

Cyclic ketones, their preparation and their use in the synthesis of amino acids

A method is provided for making an enantiomerically pure of the formula: in which R and R′ represent C1?C10 alkyl, C2?C10 alkenyl or C3?C10 cycloalkyl and the wedges signify (S)- or (R)-stereochemistry, the substituents in compound (II) being trans. Conjugate addition is carried out between an organometallic nucleophile that provides a group R as defined above and (R)-4-acetoxycyclopent-2-en-1-one, (S)-4-acetoxycyclopent-2-en-1-one or a similar compound in which acetoxy is replaced by another leaving group to give, e.g. in the case of the acetoxy compound, a trans 3,4-disubstituted addition product of formula III or IV; The acetyl group is eliminated from the addition product to give an (R)- or (S)-4-alkyl or 4-alkenyl cyclopent-2-en-1-one the compound of formula is then to be hydrogenated to give a cyclopentanone of formula (I) or conjugate addition of a second organometallic nucleophile that provides a group R′ as defined above to the compound of the above formula may be carried out to give a trans 3,4-disubstituted addition product of formula (II). One of the above compounds may be converted e.g. via an intermediate (XV)-(XVIII) (in which the substituents R and R′ and the wedges have the meanings indicated above) to a gabapentin analogue of one of the formulae shown below: in which the substituents R and R′ and the wedges also have the meanings indicated above.

Strictly regiocontrolled α-monosubstitution of cyclic carbonyl compounds with alkynyl and alkyl groups via Pd-catalyzed coupling of cyclic α-iodoenones with organozincs

The conditions for the Pd-catalyzed cross coupling of cyclic α-iodoenones, such as 2-iodo-2-cyclohexenone, with alkynylzincs have been optimized. The use of tris(o-furyl)phosphine (TFP) as a ligand and DMF as a solvent has led to the formation of α-alkynylenones in excellent yields. This optimized procedure has been applied to the synthesis of (±)-harveynone and (±)-tricholomenyn A in high yields. Investigation of related α-alkylation reactions using alkylzincs has revealed the following. Methylzinc and primary alkylzinc derivatives readily undergo Pd-catalyzed cross coupling with α-iodoenones. Although (s-Bu)2Zn also undergoes Pd-catalyzed cross coupling, only the n-Bu-substituted products were obtained, α-Benzylation and α-homobenzylation can proceed satisfactorily, whereas allylzinc and propargylzinc derivatives undergo only addition to the carbonyl group. Although some promising results have been obtained in α-homoallylation and α-homopropargylation, these reactions need to be further improved. (C) 2000 Elsevier Science Ltd.

Total synthesis with a chirogenic opening move demonstrated on steroids with estrane or 18a-homoestrane skeleton

A concept of first choice for the synthesis of the title compounds had been proposed by Dane in the late 1930s. It was soon turned down, because the opening move - a chirogenic Diels-Alder reaction - did not work. With Lewis acids as mediators, however, a successful start has been achieved now. With Ti complexes of chelating ligands (Seebach's TADDOLs (= α,α,α',α'-tetraaryl-1,3-dioxolane-4,5-dimethanols)), enantioselective formation of the desired adducts does occur. Efficient total syntheses of 2 and 3a have been accomplished.

Process for preparing oxocyclopentene derivatives

A process for preparing oxocyclopentenes of the formula: STR1 wherein R1 is hydrogen, lower alkyl or lower alkenyl and R2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, substituted or unsubstituted aryl, ar(lower)alkyl, thienyl or cycloalkyl, which comprises subjecting a furan-carbinol of the formula: STR2 wherein R1 is as defined above and R3 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, substituted or unsubstituted aryl, ar(lower)alkyl, thienyl or cycloalkyl to rearrangement, subjecting the resultant hydroxycyclopentenone of the formula: STR3 wherein R1 and R3 are each as defined above to hydrogenation and subjecting the resulting hydroxycyclopentanone of the formula; STR4 wherein R1 and R2 are each as defined above to dehydration.

Synthesis of 2-Alkyl-2-cyclopenten-1-ones. A Versatile Kinetic Alkylation-Ozonolysis Procedure for the Preparation of γ-Ketoaldehydes

A range of 2-alkyl-2-cyclopenten-1-ones including the prostaglandin precursor 2-(6-methoxycarbonylhexyl)-2-cyclopenten-1-one and the jasmonoid precursor 2--2-cyclopenten-1-one, have been prepared by a short synthetic route which begins with 6-methyl-5-hepten-2-one and generates the key 1,4-ketoaldehyde intermediates by a kinetic alkylation-ozonolysis procedure.

Oxydation anodique de β-cetocarboxylates en milieu aqueux ou hydroorganique. Application a la synthese de γ-dicetones, de cetones ethyleniques et de cetoamides

A systematic study of the anodic oxidation of β-ketocarboxylate anions in aqueous or hydroorganic solvents allows to distinguish the factors directing this reaction.Thus, it is possible by the appropriate choice of reaction medium and structure of the starting ion to synthesize products such as γ diketones, ethylenic ketones and ketoamides.