Showing papers on "Enone published in 1983"
TL;DR: In this paper, a regiospecific [3 + 2] annulation approach to highly substituted 5-membered carbocycles has been developed, which involves the reaction of (trimethylsilyl)allenes with electron-deficient alkenes and alkynes in the presence of titanium tetrachloride to afford, in a single step, a functionalized and highly substituted TMS-cyclopentene derivative.
101 citations
TL;DR: In this article, two general methods for the preparation of β-silyl-substituted divinyl ketones have been developed starting from either α, β-unsaturated aldehydes or simple ketones.
Abstract: Two general methods for the preparation of β-silyl-substituted divinyl ketones have been developed starting from either α, β-unsaturated aldehydes or simple ketones. Anhydrous FeCl3 induces the cyclization to cyclopentenones under mild conditions and in good yields with predictable and complete control over the position of the double bond in the five-membered ring. The observed effects of substituents on rate can be explained by a rate-determining cationic electrocyclization. Silyl substitution has been shown to retard the reaction.
96 citations
TL;DR: In this paper, the authors present a detailed analysis of the LSA-1983-011 abstract of the chim organ and the LCA-2013-011 paper, which is based on 2005-11-09, modified on 2017-05-12
Abstract: Note: Univ lausanne,inst chim organ,ch-1005 lausanne,switzerland. Reference LGSA-ARTICLE-1983-011doi:10.1002/hlca.19830660627 Record created on 2005-11-09, modified on 2017-05-12
95 citations
TL;DR: The authors decrit les transpositions de Claisen d'un certain nombre de glycolates allyliques O-proteges and decrit le transposition de Clausen.
Abstract: On decrit les transpositions de Claisen d'un certain nombre de glycolates allyliques O-proteges
89 citations
TL;DR: On etudie les reactions de Diels-Alder d'une hydroxycetone vinylique avec divers dienophiles in presence d'acides de Lewis as discussed by the authors.
Abstract: On etudie les reactions de Diels-Alder d'une hydroxycetone vinylique avec divers dienophiles en presence d'acides de Lewis
79 citations
TL;DR: Synthese stereospecifique utilisant l'acetoxy-2 p-anisylthio-3 butadiene-1,3 dans la reaction de Diels Alder as discussed by the authors.
Abstract: Synthese stereospecifique utilisant l'acetoxy-2 p-anisylthio-3 butadiene-1,3 dans la reaction de Diels Alder
67 citations
TL;DR: Silyl enol ethers prepared from saturated ketones and aldehydes can be converted to α,β-unsaturated ketones by the reaction of allyl carbonate in the presence of palladium-phosphine complexes as a catalyst as mentioned in this paper.
54 citations
TL;DR: On transforme une serie d'alcool allyliques derives du cholestane and de l'androstane en cetones correspondantes as discussed by the authors, and transformes them into a serie of allylique derives.
Abstract: On transforme une serie d'alcool allyliques derives du cholestane et de l'androstane en cetones correspondantes
53 citations
TL;DR: In this paper, the authors describe the preparation of Zn(Ar) 2 par ultrasonation de bromure d'aryle, ZnBr 2 et de Li dans l'ether au THF.
Abstract: Preparation de Zn(Ar) 2 par ultrasonation de bromure d'aryle, ZnBr 2 et de Li dans l'ether au THF. Agents de synthese de diverses cetones a partir d'α-enones. Donnees spectrales de masse, IR, RMN
50 citations
TL;DR: In this article, a double addition d'un reactif organocuivrique fonctionnalise suivie d'une cyclisation aldol is presented.
Abstract: Synthese en 15 etapes a partir de la dimethyl-4,4 cyclopentene-2one. La formation des noyaux cyclopentanes est obtenue par une double addition d'un reactif organocuivrique fonctionnalise suivie d'une cyclisation aldol
42 citations
TL;DR: In this paper, the existence of a series of new constituents which can be considered as Diels-Alder adducts of methyl vinyl ketone and ocimene (1, 4), myrcene (9, 10) or β-far-nesene ( 11, 12), respectively, was reported.
Abstract: The occurrence of a series of new constituents which can be considered as Diels-Alder adducts of methyl vinyl ketone and ocimene (1–4), myrcene (9, 10) or β-far-nesene ( 11, 12), respectively, was reported. Furthermore, the structures of four isomeric cyclohexene derivatives could be established as adducts 21–24 of (E, Z)- and (E, E)-1,3,5-undecatrience and methyl vinyl ketone. Another series of constituents having the norbornane skeleton represents adducts 25–32, and 33–40 of methyl cyclopentadiene and 1-octen-3-one or methyl vinyl ketone, respectively. In accordance with Alder's endo-rule the endo-isomers are preponderant in the natural as well as in the synthetic mixtures. Most of these constituents could also be identified in a lavender absolute as well as in a freshly prepared hexane extract of lavender flowers (Lavandula officinalis CHAIX).
Journal Article•
TL;DR: In this article, a pyrolyse conduit au clivage du cycle conduisant aux chloroesters ethyleniques is described, in presence of POCl 3.
Abstract: On prepare les composes du titre par cycloaddition du dichlorocetene avec des alcynes en presence de POCl 3 . La pyrolyse conduit au clivage du cycle conduisant aux chloroesters ethyleniques
TL;DR: In this paper, enol acetates derived from saturated ketones are converted to α,β-unsaturated ketones by heating with allyl methyl carbonate in MeCN by bimetallic catalysis of palladium-phosphine complex and tin methoxide.
TL;DR: Novel syntheses of 4-hydroxyandrost-4-ene-3,17-dione (Ia) and related compounds are described, some containing fluorine and several of these compounds are potent aromatase inhibitors.
Abstract: We describe novel syntheses of 4-hydroxyandrost-4-ene-3,17-dione (Ia) and related compounds, some containing fluorine. In addition we provide further evidence of the general tendency of 2- and 6-substituted androst-4-ene-3,17-diones to undergo rearrangement reactions, and thus provide new routes to 6-fluoro- and 2,6-difluoro-derivatives. Several of these compounds are potent aromatase inhibitors.
TL;DR: In this article, a 16-step synthesis of methylpallidinine from 1,4-cyclohexanedione and 3-bromoveratrole was described.
TL;DR: In this article, the precursors for the preparation of fluoro-α,β-enones were synthesized from F -alkanoyl chlorides and triethyl phosphite.
TL;DR: In this article, the highly stereoselective epoxide cleavage of 26-benzoyloxy-24,25-epoxides was found to proceed with retention at C-24.
Abstract: 24,25-Epoxy-26-hydroxy-3β-tetrahydropyranyloxycholest-5-enes (7a) and (8a), prepared by asymmetric epoxidation of the allylic alcohol (4), and 24-hydroxy-3β-tetrahydropyranyloxycholesta-5,25-dienes (11) and (12), synthesized by asymmetric reduction of the enone (6), were stereoselectively converted into 25,26- and 24,25-dihydroxycholesterol derivatives, which could be transformed into 25,26- and 24,25-dihydroxyvitamin D3. The highly stereoselective epoxide cleavage of 26-benzoyloxy-24,25-epoxides (7b), (8b), (25), and (26) was found to proceed with retention at C-24.
TL;DR: In this paper, the β-ethylenic ketones were obtained by a 1-6 addition reaction with a 1 − 6 addition reaction, corresponding to an α-ethylenrich ketone.
TL;DR: Alcenylation de chlorures d'arylmercure par des bromures ou iodures vinyliques en presence de ClRh(P(C 6 H 5 ) 3 ). Obtention de derives du styrene
Abstract: Alcenylation de chlorures d'aryl-mercure par des bromures ou iodures vinyliques en presence de ClRh(P(C 6 H 5 ) 3 ). Obtention de derives du styrene
TL;DR: On peut effectuer la synthese "one pot" par condensation du formaldehyde avec la cyclopentanone en presence de trichlorure de rhodium as mentioned in this paper.
Abstract: On peut effectuer la synthese «one pot» par condensation du formaldehyde avec la cyclopentanone en presence de trichlorure de rhodium
TL;DR: Synthese de nitriles, esters, cetones et sulfones vinyliques a partir de (chloro-1 nitro-1) ou de (bromo- 1 nitro)-1 alcanes as mentioned in this paper.
Abstract: Synthese de nitriles, esters, cetones et sulfones vinyliques a partir de (chloro-1 nitro-1) ou de (bromo-1 nitro-1) alcanes
TL;DR: In this article, aldehydes and ketones with 1,4-dianion were obtained in good yields for β-hydroxy ketones and α,β-unsaturated ketones.
TL;DR: In this paper, the reaction of potassium bromide in acetonitrile on (4a,5α,8aβ)-5-tosyloxyoctahydronaphthalen-l(2H)-one with apparent retention of configuration was described.
Abstract: 5-Bromodecalone (1) was prepared by the reaction of potassium bromide in acetonitrile on(4aα,5α,8aβ)-5-tosyloxyoctahydronaphthalen-l(2H)-one (15) with apparent retention of configuration. It was also prepared by hydrogen bromide cleavage of (3aRS,3bRS,7aSR)-octahydro-7H-cyclopenta[1,3]cyclopropa[1,2]benzen-7-one (17). On reaction with sodium potassium alloy ketone (1)gives α-decalone (33) and ketone (17) as the principal products whereas reduction with tributylstannane gives only ketone (33). Electrochemical reduction of ketone (1) gives trans-cyclodec-5-en-1-one (3) as well as ketones (17) and (33). 4-Bromodecalone (2) was prepared from(4a,4aα,8aβ)-4-tosyloxyoctahydronaphthalen-1(2H)-one (29), by the reaction with potassium bromidein acetonitrile, with inversion of configuration. Electrochemical reduction of ketone (2) gives trans-1-acetyl-2-vinylcyclohexane (36), α-decalone (33), (E)-cyclodec-4-en-1-one (4) and (laRS,-1bSR,5aRS,6aRS)-octahydrocycloprop[a]inden-6(6aH)-one(24).
TL;DR: Syntheses par cyclisation des produits d'addition du lithio-2 phenolate de lithium et d'enones ou enaldehydes as mentioned in this paper.
Abstract: Syntheses par cyclisation des produits d'addition du lithio-2 phenolate de lithium et d'enones ou enaldehydes
TL;DR: In this article, α, βethylenic ketones and α,β, α′, β′ diethylenic ketone with a stereodefined substitution pattern are easily prepared by coupling of alkenyl copper and cuprate reagents, directly obtained by carbocupration of alkynes, with acid chlorides and anhydrides.
TL;DR: In this article, a seven step synthesis of ptilocaulin via the addition of guanidine to enone 2 is described, and the synthesis is shown to work well.
TL;DR: In this article, the intramolecular photocycloaddition of E and Z olefins to a cyclohexenone has been investigated; it is concluded that the bond to C(3) in the cycloencoder is formed first to give the diradical intermediates (7a and 7b).
Abstract: The [2 + 2] intramolecular photocycloaddition of E and Z olefins to a cyclohexenone has been investigated; it is concluded that the bond to C(3) in the cyclohexenone is formed first to give the diradical intermediates (7a) and (7b).
TL;DR: In this paper, a synthesis of d1 -9(0)-methano-Δ 6(9α) -PGI 1 (1) was achieved using regiocontrolled transformation of the enone to the olefin via the allylsilane as a key step.