22323-97-3Relevant articles and documents
Reactions of α-Diazo Ketones with Selenium-based Reagents. A General Synthesis of α-Chloro-, α-Bromo, α-Phenylseleno-, α-Acetoxy-, and α-Methoxy-αβ-unsaturated Ketones
Buckley, Daniel J.,McKervey, M. Anthony
, p. 2193 - 2200 (2007/10/02)
Benzeneselenenyl derivatives, PhSe-X (X=Cl, Br, OCOCH3, and SCN) react readily with α-diazo ketones, RCOC(N2)R1 (R1=H or alkyl), with loss of nitrogen, furnishing αα-adducts of the type RCOCR1(X)SePh.The α-chloro and α-bromo adducts can be converted into α-methoxy adducts in methanol-sodium hydrogen carbonate.The utility of these adducts in synthesis is illustrated by their conversion (where structural considerations permit) via selenoxide fragmentation into α-heterosubstituted αβ-unsaturated ketones.Treatment of the series RCOCR1(X)SePh (R1=alkyl; X=Cl, Br, OCOCH3, and OCH3) with hydrogen peroxide-pyridine produces α-chloro-, α-bromo-, α-acetoxy-, and α-methoxy-αβ-unsaturated ketones, whereas treatment of series RCOCR1(X)SePh (R1=alkyl; X=Cl and Br) with lithium carbonate in dimethylformamide produces α-phenylseleno-αβ-unsaturated ketones.Several α-substituted cyclopentenones, cyclohexenones, and cycloheptenones have been synthesised in this way and acyclic examples are illustrated by the synthesis of 3-chloro-, 3-bromo-, 3-acetoxy-, 3-methoxy,-and 3-phenylselenobut-3-en-2-one from 3-diazobutan-2-one.
