Reversal of the regioselectivity in a cycloaddition of o-quinones by varying the position of alkoxy substituents

Tetrahedron Letters

Volumn 49, Issue 16, 2008, Pages 2558-2561

  Kuboki, Atsuhito ^a   Yamamoto, Toru ^a   Taira, Mamie ^a   Arishige, Tetsuya ^a   Konishi, Rina ^a   Hamabata, Mami ^a   Shirahama, Mutsumi ^a   Hiramatsu, Takeya ^a   Kuyama, Kohei ^a   Ohira, Susumu ^a  

^a OKAYAMA UNIVERSITY OF SCIENCE   (Japan)

Author keywords

1,4 Benzodioxane; Cycloaddition; o Quinone; Regioselectivity

Indexed keywords

1,4 BENZODIOXAN DERIVATIVE; ALCOHOL DERIVATIVE; QUINONE DERIVATIVE;

ARTICLE; CHEMICAL REACTION; CYCLOADDITION; SUBSTITUTION REACTION;

EID: 40849145269     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2008.02.109     Document Type: Article

References (11)

1. Kuboki A., Yamamoto T., Taira M., Arishige T., and Ohira S. Tetrahedron Lett. 48 (2007) 771
2. Magdziak D., Rodriguez A.A., Water R.W.V.D., and Pettus T.R.R. Org. Lett. 4 (2002) 285
3. Ozanne A., Pouysegu L., Depernet D., François B., and Quideau S. Org. Lett. 5 (2003) 2903
4. Methylation instead of benzylation at this stage led to the C-alkylated product as the major product. Thus, we prepared 1c from 10, not 13.
5. 3): δ -5.4, -5.0, 18.3, 25.7, 25.9, 27.5, 56.3, 62.2, 64.41, 64.43, 71.1, 76.2, 78.5, 104.1, 104.2, 107.3, 108.5, 127.6, 127.7, 128.3, 133.6, 134.8, 135.1, 136.9, 143.9, 146.9, 147.5.
6. 3): δ -5.4, -5.0, 18.3, 25.5, 25.9, 56.27, 56.31, 62.4, 64.58, 64.63, 76.1, 78.2, 101.6, 104.1, 108.1, 115.2, 123.8, 127.6, 134.9, 136.3, 143.4, 147.0, 151.2.
7. 3): δ -5.3, -5.0, 18.4, 25.7, 25.9, 56.3, 62.4, 64.5, 64.6, 71.0, 76.8, 78.2, 103.4, 104.2, 108.2, 115.4, 124.6, 126.9, 127.4, 127.6, 128.4, 135.0, 136.7, 137.4, 143.3, 147.0, 150.1.
8. 3): δ 1.72 (s, 3H), 2.23 (s, 3H), 2.33 (s, 3H), 3.72 (s, 3H), 3.82 (s, 6H), 3.87-3.92 (m, 2H), 4.00-4.04 (m, 2H), 5.30 (d, J = 10.4 Hz, 1H), 5.30 (d, J = 17.1 Hz, 1H), 5.39 (d, J = 6.0 Hz, 1H), 6.05 (ddd, J = 6.0, 10.4, 17.1 Hz, 1H), 6.50 (s, 1H), 6.66 (s, 2H), 7.17 (s, 1H).
9. 3): δ 1.78 (s, 3H), 2.23 (s, 3H), 2.31 (s, 3H), 3.80 (s, 6H), 3.83-3.86 (m, 2H), 4.01-4.05 (m, 2H), 5.01 (s, 2H), 5.22 (d, J = 10.8 Hz, 1H), 5.28 (d, J = 16.8 Hz, 1H), 5.33 (d, J = 6.0 Hz, 1H), 5.97 (ddd, J = 6.0, 10.8, 16.8 Hz, 1H), 6.49 (s, 1H), 6.60 (s, 2H), 7.19 (s, 1H), 7.28-7.38 (m, 5H).
10. 3): δ 1.01 (t, J = 7.3 Hz, 3H), 1.51 (s, 3H), 2.01-1.87 (m, 2H), 2.28 (s, 3H), 2.29 (s, 3H), 2.32 (s, 3H), 3.29-3.33 (m, 1H), 3.47-3.52 (m, 1H), 3.79 (s, 6H), 5.04 (dd, J = 5.4, 7.3 Hz, 1H), 6.57 (s, 2H), 6.74 (d, J = 2.0 Hz, 1H), 6.75 (d, J = 2.0 Hz, 1H).
11. We assume that the initial deprotonation plays an important role in the cycloaddition, because it was accelerated by addition of base in case of 1b and 1d and could not proceed under acidic conditions in all cases.