172846-87-6Relevant academic research and scientific papers
A Novel Heterocycle-Stabilized Allylic Anion Route to Cyclopropanes, 1-Ethoxy-1-vinylethylene Oxides, 1-Hydroxyalkyl 2-Methoxyethyl Ketones, 1-Hydroxyalkyl Vinyl Ketones, β-Ethoxy-β-vinylalkyl Alcohols, γ-Lactones, and β,γ-Unsaturated Carboxylic Acids
Katritzky, Alan R.,Jiang, Jinlong
, p. 7597 - 7604 (2007/10/03)
Treatment of N-(α-ethoxyallyl)benzotriazole (8) with butyllithium followed by α,β-unsaturated esters at -78 deg C formed the 1,4-adducts 11 which underwent internal disolacement of the benzotriazolyl group at 20 deg C to give cyclopropanecarboxylic esters 14 and 15.In the presence of ZnBr2, addition of anion 13 to cyclic and methyl ketones gave 1-ethoxy-1-vinylethylene oxides 25 in good yields.Epoxides 25 were subsequently converted to 1-hydroxyalkyl 2-methoxyethyl ketones 24, 1-hydroxyalkyl vinyl ketones 26, and β-ethoxy-β-vinylalkyl alcohols 27.Treatment of anion 13 with aromatic ketones or sterically hindered aliphatic ketones produced γ-alkylated adducts 31 which were hydrolyzed to β,γ-unsaturated carboxylic acids 32 (R1,R2 = aromatic) or γ-lactones 33 (R1,R2 = aliphatic).
Novel Routes to Enol Ethers, Unsymmetrical Ketones, α-Bromoalkyl Ketones, 1,4-Diketones, 2-Ethoxy-2-cyclopenetenones, and α-Keto Enamines
Katritzky, Alan R.,Zhang, Guifen,Jiang, Jinlong
, p. 7605 - 7611 (2007/10/03)
Highly regioselectve SN2' reactions of adducts 6 (readily prepared by reactions of halides with the allyl anion 12 of 11) with Grignard reagents gave enol ethers 13, which were converted (in one-pot reactions from 11) into ketones 14 and α-bromoalkyl ketones 15 in good yields.The monoprotected 1,4-diketone derivative 16 (prepared by Michael addition of the allyl anion 12 with methyl vinyl ketone) was converted both into 1,4-diketones 18 and into protected γ-hydroxyalkyl ketone 20 by propenoyl, or to both functionalities.The allyl anion 12 with α-substituted acetic esters gave α-acylated adducts 24, which underwent in situ unfavored endo-trig cyclization upon treatment with NaH and secondary amines, to give 2-ethoxy-2-cyclopenetenones 27 and 28 and α-keto enamines 25 in good yield.The mechanism for the cyclization is discussed.
