Vinylphosphonium salt mediated stereoselective synthesis of cyclobutene derivatives. A facile route to highly electron-deficient 1,3-dienes

Tetrahedron Letters

Volumn 39, Issue 35, 1998, Pages 6343-6344

  Yavari, Issa ^a   Samzadeh Kermani, Ali Reza ^a  

^a TARBIAT MODARES UNIVERSITY   (Iran)

Author keywords

[No Author keywords available]

Indexed keywords

CYCLOALKENE; CYCLOBUTENE DERIVATIVE; TOLUENE; UNCLASSIFIED DRUG;

ARTICLE; CARBON NUCLEAR MAGNETIC RESONANCE; CHEMICAL REACTION; CYCLIZATION; ELECTRON TRANSPORT; PROTON NUCLEAR MAGNETIC RESONANCE; PROTON TRANSPORT; STEREOCHEMISTRY; SYNTHESIS;

EID: 0032572878     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(98)01303-3     Document Type: Article

References (9)

1. 1. Becker, K. B. Tetrahedron, 1980, 36, 1717; Vollhardt, K. P. C. Synthesis, 1975, 765.
2. 1. Becker, K. B. Tetrahedron, 1980, 36, 1717; Vollhardt, K. P. C. Synthesis, 1975, 765.
3. 2. Patai, S. (ed.), "The Chemistry of Alkenes", 1964, Wiley, New York.
4. 3. Yavari, I. and Baharfar, R. Tetrahedron Lett., 1997, 38, 4259; J. Chem. Res.(S), 1997, 146.
5. 3. Yavari, I. and Baharfar, R. Tetrahedron Lett., 1997, 38, 4259; J. Chem. Res.(S), 1997, 146.
6. 13C NMR spectroscopy.
7. 2 (4ml) at -5 °C over 10 min.. The mixture was allowed to warm to room temperature and stirred for 24 hr. The solvent was removed under reduced pressure and the residue was purified by silica gel (Merck silica gel 60, 230-400 mesh) column chromatography using hexane-ethyl acetate as eluent. The solvent was removed under reduced pressure to afford dimethyl 4-benzoyl-1-ethoxycarbonylcyclobut-1-ene-2,3-dicarboxylate (2a) as yellow powder, 0.30g, 87%, m.p. 61-64 °C. Selected data for 2b: yellow powder, 0.32g, 76%, m.p. 83-85°C; 2c: light yellow oil, 0.32g, 84%. A solution of 2a in toluene was refluxed for 6 hr to afford quantitatively 3a: light brown powder, 0.30g, m. p. 68-70°C; 3b: dark yellow powder, 0.32g, m.p. 88-90°C; 3c: light brown oil, 0.32g.
8. 6. Analytical and spectroscopic data for compounds 2 and 3 are in agreement with the proposed structures.
9. 7. Gunther, H. "NMR Spectroscopy", 2nd ed., 1995, Wiley, New York, chapter 4.