Synthesis 2005(13): 2188-2192  
DOI: 10.1055/s-2005-869956
PAPER
© Georg Thieme Verlag Stuttgart · New York

A Novel Facile Synthetic Route to Highly Substituted 2,3-Dihydrofurans via Ammonium Ylides

Zhanjun Yanga, Mingjin Fana, Weimin Liub, Yongmin Liang*a,b
a Department of Chemistry and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China
Fax: +86(931)8912582; e-Mail: liangym1@hotmail.com;
b Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
Further Information

Publication History

Received 3 February 2005
Publication Date:
24 June 2005 (online)

Abstract

Tetrasubstituted 2,3-dihydrofurans derivatives were prepared via the reaction of quaternary ammonium salts 1 with electrophilic alkenes 2 in the presence of powered K2CO3, usually in a stereoselective manner with good to high yields. The stereochemistry of dihydrofurans was secured by NMR signals and subsequently confirmed by X-ray diffraction.

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Crystal data for trans-3ca: C18H16O3S, MW = 312.37, T = 291 (2) K, λ = 0.71073 Å, monoclinic space group P21/n, a = 9.804 (1) Å, b = 10.474 (1) Å, c = 15.324 (2) Å, α = 90.00°, β = 102.860 (2)°, γ = 90.00°, V = 1534.0(3) Å3, Z = 4, Dc = 1.353 mg/m3, µ = 0.221 mm-1, F(000) = 656, crystal size 0.38 × 0.29 × 0.21 mm, independent reflections 2860 [R(int) = 0.0142], reflections collected 7885, refinement method, full-matrix least-squares on F2, goodness-of-fit on F2 1.105, final R indices [I > 2σ (I)] R1 = 0.0373, wR2 = 0.1067, R indices (all data) R1 = 0.0427, wR2 = 0.1092, extinction coefficient 0.0117 (18), largest diff. peak and hole 0.243 eÅ-3 and -0.424 eÅ-3.

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The bond length of C8-C9 is 1.341 Å, which shows the double-bonded character; the bond length of C6-C7 is 1.562 Å.

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Z-Form.