Synthesis 2007(1): 45-50  
DOI: 10.1055/s-2006-958925
PAPER
© Georg Thieme Verlag Stuttgart · New York

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

Zhimeng Wua, Xian Huang*a,b
a Department of Chemistry, Zhejiang University (Campus Xixi), Hangzhou 310028, P. R. of China
Fax: +86(571)88807077; e-Mail: huangx@mail.hz.zj.cn;
b State Key Laboratory of Oganometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P. R. of China
Further Information

Publication History

Received 9 August 2006
Publication Date:
12 December 2006 (online)

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.

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) Å3, T = 293 (2) K, Z = 2, reflections collected/unique: 4300/3079 (R int = 0.0933), no observation [I > 2 σ(I)] 3079, parameters 194.