Diastereoselective Manipulations of Bicyclo[m.1.0]alkane Derivatives. 4. Reactions of Nucleophiles with Bicyclo[m.1.0]alk-3-en-2-ones

Journal of Organic Chemistry

Volumn 62, Issue 24, 1997, Pages 8513-8521

  Mash, Eugene A ^a   Gregg, Timothy M ^a   Baron, James A ^a  

^a University of Arizona   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0008339850     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo971359h     Document Type: Article

References (35)

1. For classification of rings by size, see: Eliel, E. L.; Wilen, S. H.; Mander, L. N. Stereochemistry of Organic Compounds; John Wiley & Sons: New York, 1994; p 678.
2. (a) Vedejs, E.; Dolphin, J. M.; Gapinski, D. M.; Mastalerz, H. In Current Trends in Organic Synthesis; Pergamon Press: Tokyo, Japan, 1982; pp 221-232.
3. (b) Still, W. C. In Current Trends in Organic Synthesis; Pergamon Press: Tokyo, Japan, 1982; pp 233-246.
4. (c) Vedejs, E. In Studies in Natural Products Chemistry; Atta-ur-Raman, Ed.; Elsevier: Amsterdam, 1991; Vol. 8; pp 205-218.
5. (d) Neeland, E. G.; Sharadendu, A.; Weiler, L. Tetrahedron Lett. 1996, 37, 5069-5072.
6. (e) Couturier, M.; Deslongchamps, P. Synlett 1996, 1140-1142.
7. (f) Nakajima, N.; Yonemitsu, O. in Studies in Natural Products Chemistry; Atta-ur-Raman, Ed.; Elsevier: Amsterdam, 1992; Vol. 11; pp 151-180.
8. (g) Suginome, H.; Kondoh, T.; Gogonea, C.; Singh, V.; Goto, H.; Osawa, E. J. Chem. Soc., Perkin Trans. 1 1995, 69-81.
9. (a) Mash, E. A.; Math, S. K.; Arterburn, J. B. J. Org. Chem. 1989, 54, 4951-4953.
10. (b) Mash, E. A.; Torok, D. S. J. Org. Chem. 1989, 54, 250-253.
11. (c) Mash, E. A.; Nelson, K. A. Tetrahedron 1987, 43, 679-692.
12. (d) Nelson, K. A.; Mash, E. A. J. Org. Chem. 1986, 51, 2721-2724.
13. See also: (e) Yeh, S.-M.; Huang, L.-H.; Luh, T.-Y. J. Org. Chem. 1996, 61, 3906-3908.
14. (a) Mash, E. A.; Nimkar, K. S.; Baron, J. A. Tetrahedron 1997, 53, 9043-9056.
15. (b) Mash, E. A.; Gregg, T. M.; Kaczynski, M. A. J. Org. Chem. 1996, 61, 2743-2752.
16. Mash, E. A.; Gregg, T. M.; Stahl, M. T. J. Org. Chem. 1997, 62, 3715-3721.
17. Reich, H. J.; Renga, J. M.; Reich, I. L. J. Am. Chem. Soc. 1975, 97, 5434-5447.
18. 13C NMR in determination of diastereomer ratios, see: Hiemstra, H.; Wynberg, H. Tetrahedron Lett. 1977, 18, 2183-2186.
19. While a proof of structure for n-butyllithium adducts 6-8 would be desirable, all were obtained as oils and were unsuitable for crystallographic analysis. The conformational mobility of these compounds and the lack of both diastereomers of 7 and 8 for comparison purposes would compromise interpretation of NOE data.
20. Corey, E. J.; Chaykovsky, M. J. Am. Chem. Soc. 1965, 87, 1353-1364.
21. Johnson, C. R.; Schroeck, C. W.; Shanklin, J. R. J. Am. Chem. Soc. 1973, 95, 7424-7431.
22. Rocquet, F.; Sevin, A. Bull. Soc. Chim. Fr. 1974, 881-887.
23. β σ bond rotation in the betaine intermediate was slower than and collapse to product.
24. Neither experimental nor theoretical studies of the relative stabilities of trans and cis enolates derived from bicyclo[m.1.0]alkan-2-ones have been reported. In the absence of geometric constraints imposed by ring size, cis enolates are thermodynamically favored for dialkyl ketones. However, the difference in energy can be small. See: (a) ref 1, pp 897-905, and references therein, (b) Graham, R. J.; Weiler, L. Tetrahedron Lett. 1991, 32, 1027-1030. (c) Still, W. C.; Galynker, I. Tetrahedron 1981, 37, 3981-3996.
25. Neither experimental nor theoretical studies of the relative stabilities of trans and cis enolates derived from bicyclo[m.1.0]alkan-2-ones have been reported. In the absence of geometric constraints imposed by ring size, cis enolates are thermodynamically favored for dialkyl ketones. However, the difference in energy can be small. See: (a) ref 1, pp 897-905, and references therein, (b) Graham, R. J.; Weiler, L. Tetrahedron Lett. 1991, 32, 1027-1030. (c) Still, W. C.; Galynker, I. Tetrahedron 1981, 37, 3981-3996.
26. Neither experimental nor theoretical studies of the relative stabilities of trans and cis enolates derived from bicyclo[m.1.0]alkan-2-ones have been reported. In the absence of geometric constraints imposed by ring size, cis enolates are thermodynamically favored for dialkyl ketones. However, the difference in energy can be small. See: (a) ref 1, pp 897-905, and references therein, (b) Graham, R. J.; Weiler, L. Tetrahedron Lett. 1991, 32, 1027-1030. (c) Still, W. C.; Galynker, I. Tetrahedron 1981, 37, 3981-3996.
27. For an overview, see: Organocopper Reagents; Taylor, R. J. K., Ed.; Oxford University Press: Oxford, 1994.
28. (a) Corey, E. J.; Hannon, F. J. Tetrahedron Lett. 1990, 31, 1393-1396.
29. (b) Corey, E. J.; Boaz, N. W. Tetrahedron Lett. 1985, 26, 6015-6018.
30. Frantz, D. E.; Singleton, D. A.; Snyder, J. P. J. Am. Chem. Soc. 1997, 119, 3383-3384 and references cited therein.
31. The rotation of 3-methylcyclohexadecanone has not been reported.
32. The variability in the ratios of ring-opened to ring-expanded products in the dissolving metal reductions of the different bicyclic ketones is notable (Table 4). Ring opening is thought to proceed by electron transfer to the carbonyl to give a radical anion, followed by subsequent cleavage of one of the α,β-cyclopropane bonds. The cyclopropane bond which breaks is normally the one with greater σ-π* overlap. Thus, the regioselectivity in this reaction is determined by the dominant conformers of the cyclopropyl-carbonyl torsion. Since electron transfer and ring opening, with the accompanying release of strain energy, is an extremely fast process, the ground state conformers of substrates may serve as useful models for predicting the regiochemical course of such reactions. As an illustration, reduction of 15a proceeded to give almost exclusively ring-expanded product 20. On consideration of the lowest energy conformer, 15a-1, the dihedral angle from the carbonyl to the internal cyclopropane bond is 76° - very nearly optimal - while that from the carbonyl to the external bond is 7°. equation presented Optimal σ-π* Overlap 15a-1
33. Molecular mechanics parameters are available for simple enolates, but the applicability of these parameters to enolates derived from bicyclo[m.1.0]alkan-2-ones is untested. Studies to clarify this point are in progress.
34. For the General Experimental Section, see ref 4b.
35. The author has deposited atomic coordinates for 16a with the Cambridge Crystallographic Data Centre. The coordinates can be obtained, on request, from the Director, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, CB2 1EZ, U.K.