Allyldiisopropylphenylsilane as a synthetic equivalent of 2-hydroxy-1,3-dipole. Stereoselective synthesis of cyclopentanols

Abstract

ZrCl₄-Promoted [3 + 2] cycloaddition of allyldiisopropylphenylsilane to α,β-unsaturated ketones proceeds smoothly to afford silyl-substituted cyclopentanes highly stereoselectively. Oxidative cleavage of the carbon–silicon bond leads to stereoselective formation of cyclopentanols.

References

1. W. Carruthers, Cycloaddition Reactions in Organic Synthesis, Pergamon, Oxford, 1990.
2. For reviews: J. S. Panek, Silicon Stabilization, in Comprehensive Organic Synthesis, ed. B. M. Trost and I. Fleming, Pergamon, Oxford, 1991, vol. 1, p. 579; C. E. Masse and J. S. Panek, Chem. Rev., 1995, 95, 1293; H.-J. Knölker, J. Prakt. Chem., 1997, 339, 304.
3. For the preparation of cyclopentanes: (a) R. L. Danheiser, T. Takahashi, B. Bertok and B. R. Dixon, Tetrahedron Lett., 1993, 34, 3845; (b) H.-J. Knölker, N. Foitzik, H. Goesmann and R. Graf, Angew. Chem., Int. Ed. Engl., 1993, 32, 1081; (c) H.-J. Knölker and R. Graf, Tetrahedron Lett., 1993, 34, 4765; (d) J. S. Panek and N. F. Jain, J. Org. Chem., 1993, 58, 2345; (e) H.-J. Knölker and R. Graf, Synlett, 1994, 131; (f) G. P. Brengel, C. Rithner and A. I. Meyers, J. Org. Chem., 1994, 59, 5144; (g) H.-J. Knölker, P. G. Jones and R. Graf, Synlett, 1966, 1155; (h) H.-J. Knölker, N. Foitzik, H. Goesmann, R. Graf, P. G. Jones and G. Wanzl, Chem. Eur. J., 1997, 3, 538; (i) W. S. Murphy and D. Neville, Tetrahedron Lett., 1997, 38, 7933.
4. For the preparation of 5-membered heterocycles: H. Sugimura, Tetrahedron Lett., 1990, 31, 5909; J. S. Panek and R. Beresis, J. Org. Chem., 1993, 58, 809; J. S. Panek and R. T. Beresis, J. Am. Chem. Soc., 1993, 115, 7898; D. Schinzer and G. Panke, J. Org. Chem., 1996, 61, 4496.
5. For the preparation of cyclobutanes: H. Monti, G. Audran, G. Léandri and J.-P. Monti, Tetrahedron Lett., 1994, 35, 3073; H.-J. Knölker, G. Baum and R. Graf, Angew. Chem., Int. Ed. Engl., 1994, 33, 1612.
6. T. Akiyama, K. Ishikawa and S. Ozaki, Chem. Lett., 1994, 627; T. Akiyama, T. Yasusa, K. Ishikawa and S. Ozaki, Tetrahedron Lett., 1994, 35, 8401.
7. T. Akiyama and M. Kirino, Chem. Lett., 1995, 723.
8. T. Akiyama and M. Yamanaka, Synlett, 1996, 1095.
9. (a) E. W. Colvin, Oxidation of Carbon-Silicon Bonds, in Comprehensive Organic Synthesis, ed. B. M. Trost and I. Fleming, Pergamon, Oxford, 1991, vol. 7, p. 641; (b) G. R. Jones and Y. Landais, Tetrahedron, 1996, 52, 7599.
10. For example: C. Palomo, J. M. Aizpurua, R. Urchegui and M. Iturbutu, J. Org. Chem., 1992, 57, 1571; see also ref. 9b, p. 7653.
11. Bulky silanes or silyl ethers which have been oxidised to alcohols: J. H. Smitrovich and K. A. Woerpel, J. Org. Chem., 1996, 61, 6044; P. M. Bodnar, W. S. Palmer, J. T. Shaw, J. H. Smitrovich, J. D. Sonnenberg, A. L. Presley and K. A. Woerpel, J. Am. Chem. Soc., 1995, 117, 10 575; C. Gibson, T. Buck, M. Walker and R. Brückner, Synlett, 1998, 201.
12. H.-J. Knölker and G. Wanzl, Synlett, 1995, 378.
13. G. P. Brengel and A. I. Meyers, J. Org. Chem., 1996, 61, 3230.
14. Although Knölker reported one example of the cycloaddition of 1, transformation of the silyl group into an OH group has not been reported.^3b,3h.
15. Tin(IV) chloride mediated reaction gave rise to 2a in 58% yield.
16. A typical experimental procedure for the preparation of 2a is described (Entry 1, Table 1). To a solution of methyl vinyl ketone (25.2 mg, 0.36 mmol) in toluene (1.0 ml) was added zirconium(IV) chloride (95.2 mg, 0.41 mmol) at –20 °C. After being stirred at that temperature for 10 min, the suspension was cooled to –78 °C and allyldiisopropylphenylsilane (94.9 mg, 0.408 mmol) in toluene (0.8 ml) was added. The reaction mixture was allowed to warm to –20 °C over 5 h and was quenched by addition of 5% aqueous KHSO₄. The aqueous layer was extracted with ethyl acetate and the combined organic layers were washed with brine, dried over anhydrous Na₂SO₄, and concentrated to dryness. Purification of the crude mixture by column chromatography (SiO₂, hexane–ethyl acetate = 15∶1, v/v) gave 2a(102 mg, 89%).
17. It should be noted that allyl-tert-butyldiphenylsilane which was useful for the oxetane formation was not effective for the present cyclopentane annulation; the corresponding cycloadduct was obtained in only modest yield and oxidative cleavage of the tert-butyldiphenylsilyl group was not successful under the above conditions.
18. I. Flemming, R. Henning and H. Plaut, J. Chem. Soc., Chem. Commun., 1984, 29.
19. The yields of fluorosilane 3b with BF₃·2CH₃CO₂H, HF·Py and Buⁿ₄N·F were 84, 0 and 0% respectively.
20. K. Tamao, N. Ishida and M. Kumada, J. Org. Chem., 1983, 48, 2120; K. Tamao and N. Ishida, J. Organomet. Chem., 1984, 269, C37.