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

Article abstract of DOI:10.1021/jo00128a036

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).