- Stereoselective Synthesis of (E)- and (Z)-γ,δ-Unsaturated Ketones Using trans-2-Phenylthiocyclobutyl Ketones
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The reaction of 1-methoxymethyl-2-phenylthiocyclobutanes with phenylthiotrimethylsilane followed by hydrolysis gave (E)- and (Z)-γ,δ-unsaturated ketones with high stereoselectivity.The starting materials were easily prepared by the stereoselective addition of Grignard reagents to trans-2-phenylthiocyclobutyl ketones.
- Fujiwara, Tooru,Iwasaki, Toshiaki,Takeda, Takeshi
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p. 1321 - 1324
(2007/10/02)
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- Isoprenoid Chain Elongations by Claisen Rearrangements Using Acetals as Precursors of Vinyl Ethers
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Claisen rearrangements of allyl vinyl ethers, formed in situ by the acid catalyzed reaction of dimethyl acetals of acetaldehyde, acetone and isopropenyl methyl ketone with different types of allylic alcohols, have been compared.The primary, secondary and tertiary allylic alcohols used in the investigation were selected to serve as models for isoprenoid synthesis.The basis for two feasible methods that can be iterated to create isoprenoid chains has been investigated.
- Baeckstroem, Peter,Li, Lanna
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p. 6521 - 6532
(2007/10/02)
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- Allylic Carbonates. Efficient Allylating Agents of Carbonucleophiles in Palladium-Catalyzed Reactions under Neutral Conditions
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Allylation of β-keto esters or malonates was carried out in good yields under neutral conditions by using allylic carbonates in the presence of palladium-phospine catalyst.Although simple ketones, esters, nitriles, and sulfones hardly react with allylic carbonates, α-alkenyl or α-aryl ketones, esters, nitriles, and sulfones were also allylated by using palladium-bis(diphenylphosphino)ethane catalyst under neutral conditions.
- Tsuji, Jiro,Shimizu, Isao,Minami, Ichiro,Ohashi, Yukihiro,Sugiura, Teruo,Takahashi, Kazuhiko
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p. 1523 - 1529
(2007/10/02)
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- PALLADIUM-CATALYZED REARRANGEMENT OF ALLYLIC ESTERS OF ACETOACETIC ACID TO GIVE γ,δ-UNSATURATED METHYL KETONES
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Various allylic esters of acetoacetic acid undergo rearrangement to give γ,δ-unsaturated methyl ketones in high yields with elimination of carbon dioxide under mild conditions in the presence of catalytic amounts of Pd(OAc)2 and PPh3.
- Shimizu, Isao,Yamada, Toshiro,Tsuji, Jiro
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p. 3199 - 3202
(2007/10/02)
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