- Pd(0)-Catalyzed Conjugate Addition of Benzylzinc Chlorides to α,β-Enones in An Atmosphere of Carbon Monoxide: Preparation of 1,4-Diketones
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Pd(0)-catalyzed conjugate addition of benzylzine chloride to methyl vinyl ketone in the presence of chlorotrimethylsilane and lithium chloride in an atmosphere of carbon monoxide at room temperature afforded 1-phenyl-2,5-hexanedione monosilyl enol ether. In this catalytic carbonylation, four components are connected in one reaction. Successive acidic workup generated a variety of 1,4-diketones from substituted benzylzine chlorides or related compounds and α,β-enones. Some products were converted to cyclopentenones or five-membered heterocyclic compounds containing an N, O, or S atom.
- Yuguchi, Motoki,Tokuda, Masao,Orito, Kazuhiko
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p. 908 - 914
(2007/10/03)
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- A convenient synthesis of 1,4-diketones
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A simple and short synthesis of 1,4-diketones was achieved via 2-chloro-5-methylthio-2,5-hexadienes and their hydrolysis with titanium tetrachloride.
- Motoyoshiya,Hongo,Tanaka,Hayashi
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p. 997 - 1000
(2007/10/02)
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- A facile synthesis of 1,4-diketones
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1,4-Diketones may conveniently be synthesized by the addition of 2-methylcyclopropenyllithium to N-methoxy-N-methylcarboxamides followed by hydrolysis of intermediate cyclopropyl ketone adducts on silica gel. The new method has been applied to the synthesis of cis-jasmone.
- Bergman,Nilsson,Wickberg
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p. 2783 - 2786
(2007/10/02)
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- One-Step Synthesis of 1,4-Diketones by Nucleophilic Reaction to Tricarbonyl Complexes of α,β-Unsaturated Ketones
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Tricarbonyliron complexes of 3-buten-2-one, 3-penten-2-one, and 4-phenyl-3-buten-2-one reacted with organolithium and Grignard reagents to afford 1,4-diketones in one step, some of the products are amenable to convertion to natural products.
- Kitahara, Haruo,Tozawa, Yasuyuki,Fujita, Seikou,Tajiri, Akio,Morita, Noboru,Asao, Toyonobu
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p. 3362 - 3364
(2007/10/02)
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- AN IMPROVED, SIMPLE SYNTHESIS OF 3-METHYL-2-(4-METHYLPHENYL) CYCLOPENTEN-2-ONE: AN IMPORTANT INTERMEDIATE IN CUPARENE SYNTHESIS
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Conjugate addition of phenyl-1-methyl-4-(2-nitroethyl) to methyl vinyl ketone in presence of basic alumina, following by Nef reaction and basic cyclization, affords 3-methyl-2-(4-methyl phenyl) cyclopenten-2-one in good yield.
- Ballini, Roberto,Petrini, Marino,Marotta, Emanuela
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p. 543 - 548
(2007/10/02)
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- Synthetic Studies on Aromatic Sesquiterpenoids: Synthesis of Curcumene Ether by Olefin Cyclisation
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The acid-catalysed cyclisation of the olefinic β-hydroxy sulphides (15a) and (15b) gave 3-phenylthiocurcumene ether as a diastereoisomeric mixture together with 5,5-dimethyl-4-phenylthio-1-p-tolylcyclohex-1-ene (16) and 2-methyl-3-(1-methyl-1-phenylthioethyl)-2-p-tolylcyclobutan-1-ol (19).The diastereoisomers (17) and (18) were converted into curcumene ether (24).Treatment of the silyl enol ether (7) with benzenesulphenyl chloride yielded 5-phenylthiomethyl-2-tetrahydrofuran (8) and 5-chloro-1,6-bis(phenylthio)-1-p-tolylhexan-2-one (9). 1-p-Tolylhexane-2,5-dione (10) was also synthesised from (5) employing a palladium-catalysed oxidation, and this result constitutes a formal total synthesis of cuparene (11).
- Kametani, Tetsuji,Kawamura, Kuniaki,Tsubuki, Masayoshi,Honda, Toshio
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p. 1305 - 1310
(2007/10/02)
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- A CONVENIENT METHOD FOR THE SYNTHESIS OF 4-CHLORO-3-ALKENOIC ACID, A NEW USEFUL SYNTHETIC BLOCK FOR 4-OXOALKANOIC AND 4-OXO-2-ALKENOIC ACIDS
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Easily available material, β-(1-chlorovinyl)-β-propiolactone reacted with organocopper reagents to afford 4-chloro-3-alkenoic acids in high yields.The acids were easily transformed into two kinds of useful carboxylic acids such as 4-oxoalkanoic and 4-oxo-(E)-2-alkenoic acids leading to various natural products.
- Kawashima, Masatoshi,Fujisawa, Tamotsu
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p. 1851 - 1854
(2007/10/02)
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- A Simple and Efficient Total Synthesis of the Sesquiterpenes Cuparene and Iso-α-curcumene, from Furan Derivatives
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3,3-Dimethyl-2-p-tolylcyclopentanone (7) was synthesised by 1,4-addition of lithium dimethylcuprate to 3-methyl-2-p-tolylcyclopentenone (6), which was derived from 5-methyl-2-(4-methylbenzyl)furan (4) through the diketone (5).Starting from the same intermediate (5), 2-p-tolylheptan-6-one (16) was also synthesised.These results constitute formal total syntheses of cuparene (9) and iso-α-curcumene (17) respectively.
- Kametani, Tetsuji,Tsubuki, Masayoshi,Nemoto, Hideo
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p. 759 - 761
(2007/10/02)
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