Intermolecular Mn(OAc)₃-Mediated Oxidative Free-Radical Reaction of Dimethyl Malonate or Ethyl Cyanoacetate with Allenes: An Efficient Synthesis of Furan-2(5H)-ones or Dimethyl 2-(2-Oxoethylidene)malonates

Abstract

Manganese(III)-mediated free-radical reaction of allenes with dimethyl malonate or ethyl cyanoacetate in acetic acid pro­duces furan-2-(5H)-one derivatives (but-2-en-4-olides) or dimethyl 2-(2-oxoethylidene)malonates in moderate yields. The possible reaction mechanism is also discussed.

Key words

allene - radical reaction - manganese(III)

References

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8

Crystal data for compound 5a: C₁₅H₁₆O₅, M = 276.28, triclinic, space group P-1, Mo KR, final R indices [I > 2 σ(I)], R ¹ = 0.0562, wR ² = 0.1254, a = 5.6333 (10), b = 8.1532 (14), c = 15.953 (3) Å, α = 96.899 (4)°, β = 91.399 (3)°, γ = 92.189 (4)°, V = 726.5 (2) ų, T = 293 (2) K, Z = 2, reflections collected/unique: 4300/3079 (R _int = 0.0933), no observation [I > 2 σ(I)] 3079, parameters 194.