Asymmetric aldol reactions of achiral 2-phenylsulfanyl aldehydes with small- and medium-sized carbocyclic rings: the synthesis of homochiral spirocyclic lactones, pyrrolidines and tetrahydrofurans

Abstract

Chiral boron enolates based on the 1,3-oxazolidin-2-one auxiliary react with achiral 1-phenyl-sulfanylcycloalkanecarbaldehydes in anti- and syn-selective aldol processes to give the corresponding aldol products with moderate to excellent levels of diastereo- and enantio-control. Stereospecific cyclisation via an asymmetric episulfonium (thiiranium) ion leads to optically pure spirocyclic compounds in high chemical yields.

References

1. (a) V. K. Aggarwal and S. Warren, Tetrahedron Lett., 1986, 27, 101; (b) I. Coldham and S. Warren, J. Chem. Soc., Perkin Trans. 1, 1992, 2303.
2. (a) Preliminarycommunications: K. Chibale and S. Warren, Tetrahedron Lett., 1991, 32, 6645; (b) K. Chibale, R. C. Hartley, K. P. Jenkins, M. Simons, S. Warren and I. C. Richards, Tetrahedron Lett., 1993, 34, 6783.
3. K. Chibale and S. Warren, Tetrahedron Lett., 1994, 35, 3991.
4. V. K. Aggarwal, I. Coldham, S. McIntyre and S. Warren, J. Chem. Soc., Perkin Trans. 1, 1991, 451.
5. (a) D. A. Evans, J. Bartroli and T. L. Shih, J. Am. Chem. Soc., 1981, 103, 2127; (b) J. R. Gage and D. A. Evans, Org. Synth., 1989, 68, 77.
6. A. de Groot and B. J. M. Jansen, Tetrahedron Lett., 1981, 22, 887; A. de Groot and B. J. M. Jansen, Synthesis, 1985, 434; J. Otera, Synthesis, 1988, 95.
7. R. O. Duthaler, P. Herold, S. Wyler-Helfer and M. Riediker, Helv. Chim. Acta, 1990, 73, 659.
8. H. Danda, M. M. Hansen and C. H. Heathcock, J. Org. Chem., 1990, 55, 173.
9. M. A. Walker and C. H. Heathcock, J. Org. Chem., 1991, 56, 5747.
10. C. H. Heathcock, M. C. Pirrung and J. E. Sohh, J. Org. Chem., 1979, 44, 4294.
11. M. Hannaby, P. Judson and S. Warren, J. Chem. Soc., Perkin Trans. 1, 1991, 2609.
12. W. H. Pirkle, D. L. Sikkenga and M. S. Pavlin, J. Org. Chem., 1977, 42, 384.
13. R. C. Hartley, Ph.D. Thesis, University of Cambridge, 1991..
14. V. K. Aggarwal, Ph.D. Thesis, University of Cambridge, 1986..
15. (a) V. K. Aggarwal, I. Coldham, S. McIntyre, F. H. Sansbury, M. J. Villa and S. Warren, Tetrahedron Lett., 1988, 29, 4885; (b) S. McIntyre, F. H. Sansbury and S. Warren, Tetrahedron Lett., 1991, 32, 5409; (c) F. H. Sansbury and S. Warren, Tetrahedron Lett., 1992, 33, 539.
16. J. I. Levin, E. Turos and S. M. Weinreb, Synth. Common., 1982, 12, 989.
17. I. Coldham and S. Warren, J. Chem. Soc., Perkin Trans. 1, 1993, 1637.
18. J. A. Dale, D. L. Dull and H. S. Mosher, J. Org. Chem., 1969, 34, 2543.
19. T. D. Penning, S. W. Djuric, R. A. Haack, V. J. Kalish, J. M. Miyashiro, B. W. Rowell and S. S. Yu, Synth. Commun., 1990, 70, 307.