Practical radical cyclisations leading to the construction of near-stereopure quaternary carbon stereogenic centres

Abstract

The 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl auxiliary is effective in directing bromopropargyloxy additions to the olefinic bonds of vinylogous esters/carbonates; in the presence of AIBN and 1-ethylpiperidinium hypophosphite, the adducts undergo highly stereoselective reductive radical cyclisations in which quaternary carbon stereogenic centres are generated.

References

1. S. F. Martin, Tetrahedron, 1980, 36, 419; K. Fuji, Chem. Rev., 1993, 93, 2037; E. J. Corey and A. Guzman–Perez, Angew. Chem., Int. Ed., 1998, 37, 388.
2. M.–Y. Chen, J.–M. Fang, Y.–M. Tsai and R.–L. Yeh, J. Chem. Soc., Chem. Commun., 1991, 1603; P. A. Zoretic, X. Weng, C. K. Biggers, M. S. Biggers, M. L. Caspar and D. G. Davis, Tetrahedron Lett., 1992, 33, 2637; B. B. Snider and Q. Zhang, Tetrahedron Lett., 1992, 33, 5921; Q. Zhang, R. M. Mohan, L. Cook, S. Kazanis, D. Peisach, B. M. Foxman and B. B. Snider, J. Org. Chem., 1993, 58, 7640.
3. M. S. Idris, D. S. Larsen, A. Schofield, R. J. Stoodley and P. D. Tiffin, Tetrahedron Lett., 1995, 36, 3251.
4. C. Chatgilialoglu, Chem. Rev., 1995, 95, 1229.
5. D. H. R. Barton, D. O. Jang and J. C. Jaszberenyi, J. Org. Chem., 1993, 58, 6838.
6. B. Giese, M. Bulliard and H.-G. Zeitz, Synlett, 1991, 425.
7. A. Srikrishna, S. Nagaraju and G. V. R. Sharma, J. Chem. Soc., Chem. Commun., 1993, 285.
8. D. P. Curran, N. A. Porter and B. Giese, Stereochemistry of Radical Reactions, VCH, Weinheim, 1996, ch. 5.
9. R. Kaushal, S. Sovani and S. S. Deshapande, J. Indian Chem. Soc., 1942, 19, 107.