1997 oxazole derivatives

oxazole derivativesR 0220

36 - 145Efficient Synthesis of 4-Ethenylidene-2-oxazolidinones via Palladium-Catalyzed Aminocyclization of 2-Butyn-1,4-diol Biscarbamates. —Treatment of 2-butyn-1,4-diol biscarbamates such as (I) with catalytic Pd(0)and triethylamine gives fair yields of the allenic products (II) and (III). Whenα-methylacryloyl substituted educts (cf. (IV)) are employed, a higher reactiontemperature provides (VI) as the sole product, most probably via cyclizationof the primary formed product ( V). — (KIMURA, M.; WAKAMIYA, Y.;HORINO, Y.; TAMARU, Y.; Tetrahedron Lett. 38 (1997) 22, 3963-3966; Dep.Appl. Chem., Fac. Eng., Nagasaki Univ., Bunkyo, Nagasaki 852, Japan; EN)

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