[4+3]Cycloaddition Reactions: Synthesis of 9,10-Dimethoxy-9,10-propanoanthracen-12-ones

Abstract

Cycloaddition of 9,10-dimethoxyanthracene (1) to tetrabromoacetone (2a) under a variety of conditions afforded isomers 3a,b; reductive debromination of 3a,b afforded 4, while reduction with NaBH₄ gave alcohol 6 which on reductive debromination gave olefin 7; reaction of 1 with 2b gave isomers 8a,b.

References

1. (a) H. M. R. Hoffmann, Angew. Chem., Int. Ed. Engl., 1973, 12, 819; (b) H. M. R. Hoffmann, Angew. Chem., Int. Ed. Engl., 1984, 23, 1; (c) D. I. Rawson, B. K. Carpenter and H. M. R. Hoffmann, J. Am. Chem. Soc., 1979, 101, 1786; (d) N. N. Joshi and H. M. R. Hoffmann, Tetrahedron Lett., 1986, 27, 687.
2. (a) R. Noyori and Y. Hayakawa, Org. React. (N.Y.), 1983, 29, 163; (b) R. Noyori, Acc. Chem. Res., 1979, 12, 61; (c) H. Takaya, S. Makino, Y. Hayakawa and R. Noyori, J. Am. Chem. Soc., 1978, 100, 1765.
3. J. Mann, Tetrahedron, 1986, 42, 4611.
4. J. H. Rigby and F. C. Pigge, Organic Reactions, 1997, 51, 351.
5. R. J. Giguere, D. I. Rawson and H. M. R. Hoffmann, Synthesis, 1978, 902.
6. R. G. Doerr and P. S. Skell, J. Am. Chem. Soc., 1967, 89, 4684.
7. (a) Molecular mechanics calculations (MM3) were performed using the computer program PCMODEL 486 version 4, available from Serena Software; (b) M. H. Schwartz, S. M. Rosenfeld, C. I. Lee, J. P. Jasinski and E. H. Dardon, Tetrahedron Lett., 1992, 33, 6275; (c) K. Okada, H. Kawai and M. Oda, Tetrahedron Lett., 1992, 33, 257; (d) K. Sakakibara and N. L. Allinger, J. Org. Chem., 1995, 60, 4044.
8. C. A. M. Afonso, W. B. Motherwell, D. M. O'Shea and L. R. Roberts, Tetrahedron Lett., 1992, 33, 3899.