The asymmetric synthesis of 2,3-benzocarbapenems by intramolecular aryl radical cyclizations

Tetrahedron Asymmetry

Volumn 7, Issue 8, 1996, Pages 2203-2206

  Alcaide, Benito ^a   Moreno, Angel M ^a   Rodríguez Vicente, Alberto ^a   Sierra, Miguel A ^a  

^a UNIVERSIDAD COMPLUTENSE DE MADRID   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

CARBAPENEM DERIVATIVE;

ARTICLE; CHIRALITY; DRUG SYNTHESIS; NUCLEAR MAGNETIC RESONANCE; PRIORITY JOURNAL; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0030221457     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/0957-4166(96)00271-6     Document Type: Article

References (18)

1. 1. (a) Chemistry and Biology of β-Lactam Antibiotics; Morin, R. B., Gorman, M. eds; Academic Press., New York, 1982; Vols 1-3.
2. (b) Spratt, B. G. Science 1994, 264, 388-393.
3. 2. Joyeau, R.; Yadav, L. D. S.; Wakselman, M. J. Chem. Soc., Perkin Trans. 1, 1987, 1899-1907.
4. 3. Gilchrist, T. L.; Graham, K.; Coulton, S. Tetrahedron Lett. 1995, 36, 8693-6.
5. 4. The use of radical chemistry in the synthesis of β-lactam antibiotics has attracted considerable attention previously.See, for example: (a) Kant, J.; Walker, D. G. In The Organic Chemistry of β-Lactams; Georg, G. I., Ed.; VCH: Weinheim, 1993; Ch. 3, p 159-167.
6. (b) Bachi, M. D. In Recents Advances in the Chemistry of β-Lactam Antibiotics; Bentley, P. H.; Southgate, R., Eds.; Spec. Pub. No. 70; Roy. Soc. Chem.: London, 1989; Ch. 6.
7. (c) Anaya, J.; Barton, D. H. R.; Gero, S. D.; Grande, M.; Martín, N.; Tachdijian, C. Angew. Chem. Int. Ed. Engl. 1993, 32, 867-869.
8. (d) Bachi, M. D.; Bar-Ner, N. BioMed. Chem. Lett. 1993, 3, 2439-2447 and references therein.
9. 5. While this work was in progress a related aryl radical cyclization to 1,2-benzocarbacephams from N-allyl-4-(o-bromophenyl)-2-azetidinones has been reported. See: Banik, B. K.; Subbaraju, G. V.; Manhas, M. S.; Bose, A. K. Tetrahedron Lett. 1996, 37, 1363-6.
10. 6. We have previously reported the radical synthesis of tin-functionalized carbapenams from enyne-β-lactams: Alcaide, B.; Benito, J.; Rodríguez-Campos, I. M.; Rodríguez-López, J.; Rodríguez-Vicente, A.; Sierra, M. A.; García-Granda, S.; Gutíerrez-Rodríguez, A. Tetrahedron: Asymmetry, 1995, 6, 1055-8.
11. 7. For a review on the ketene-imine approach to β-lactams, see: Georg, G. I.; Ravikumar, V. T. In The Organic Chemistry of β-Lactams; Georg, G. I., Ed.; VCH Publishers Inc., New York, 1993; Ch. 6, p 295-368
12. 8. Evans, D. A.; Sjogren, E. B. Tetrahedron Lett., 1985, 26, 3783-3786.
13. 9. Dichlorophenylphosphate was used as the condensating agent in these cases. See: Arrieta, A.; Lecea, B.; Cossío, F. P.; Palomo, C. J. Org. Chem. 1988, 53, 3784-3791.
14. 3SnH (1.2 mmol), and AIBN (0.1 mmol) was refluxed in dry benzene (20 mL) under an argon atmosphere, until complete disappearance of the starting substrate (t.l.c., 1,5-3h). The resulting crude reaction mixture was treated with 10% aqueous solution of KF (20 mL) for 30 minutes. The organic layer was separated, dried and the solvent evaporated in vacuo to give the reaction mixture which was purified by flash chromatography. Partial decomposition was observed for 6-benzyloxy-2,3-benzocarbapenam 1b while attempting purification. All pure compounds gave satisfactory spectroscopic and analytical data.
15. 11. Removal of the organotin halides by a solution of KF in water is essential for an appropriate chromatographic purification of compounds 1. See: Leibner, J. E.; Jacobus, J. J. Org. Chem. 1979, 44, 449-450.
16. 3, 300MHz) δ: 1.19 (d, 3H, J =7.5), 3.35 (m,1H), 3.55 (d, 1H, J=17.1), 4.18 (t, 1H, J=7.8 ), 4.64 (d, 1H, J=17.4), 4.75 (t, 1H, J=9.3), 5.19 (t, 1H, J=8.4), 5.51 (dd, 1H, J=5.1; J=7.0), 6.56 (d, 1H, J=7.0), 7.1-7.9 (m,9H).
17. 13. For a related ionic C3-C4 ring fragmentation, see: Alcaide, B.; Martín-Cantalejo, Y.; Rodríguez-López, J.; Sierra, M. A. J. Org. Chem. 1993, 58, 4767-70.
18. 14. Horwell, D. C.; Morrell, A. I.; Roberts, E. Tetrahedron Lett., 1995, 36, 459-460, and references cited therein.