Synthesis of fused azacycle via Overman rearrangement and ring-rearrangement metathesis as key steps
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Results and discussion
Our journey toward the synthesis of azacycle 1 begins with the preparation of the key precursor 2 (Fig. 1). In this regard a readily available dicyclopentadiene (5) was oxidized with SeO2 followed by PCC oxidation that delivered the reported tricyclic enone 7.10 Stereo selective 1,2 reduction of enone 7 with DIBAL-H at −78 °C gave the known 1β-dicyclopentadienol (4).11
Next, the 1β-dicyclopentadienol (4) was treated with trichloroacetonitrile in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene
Conclusion
In summary, we have demonstrated the utility of RRM strategy with the norbornene derivative 2 to deliver the tricyclic compound 1 involving a short synthetic sequence. For the first time, we have shown that Overman rearrangement in combination with RRM is a useful strategy to generate azacyclic compound 1. Here, we have used an inexpensive and commercially available starting material such as dicyclopentadiene (5).
Acknowledgements
We thank the Department of Science and Technology (DST), New Delhi for the financial support and the Sophisticated Analytical Instrument Facility (SAIF), IIT-Bombay for recording spectral data. S. K. thanks the Department of Science and Technology for the award of a J. C. Bose fellowship. O. R. thanks the University Grants Commission, New Delhi for the award of a research fellowship.
References and notes (12)
- et al.
Synlett
(2012)Molecular Rearrangements in Organic synthesis
(2016) - et al.
Tetrahedron
(1959)J. Am. Chem. Soc.
(1957)et al.J. Chin. Chem. Soc.
(2009) - et al.
Tetrahedron Lett.
(1999)et al.J. Org. Chem.
(1998) - et al.
Nat. Prod. Rep.
(2004)et al. et al. et al.J. Am. Chem. Soc.
(2014)et al.Chem. Soc. Rev.
(2013) - et al. et al.
Eur. J. Org. Chem.
(2014)et al.Synlett
(2015)J. Am. Chem. Soc.
(1974)et al.Org. Lett.
(2015)et al.Eur. J. Org. Chem.
(2015)et al.J. Org. Chem.
(2014)et al.J. Org. Chem.
(2014)et al.Synthesis
(2009) - et al.
Beilstein J. Org. Chem.
(2015)et al.Eur. J. Org. Chem.
(2014)et al.Beilstein J. Org. Chem.
(2015)et al.J. Am. Chem. Soc.
(2013)et al.Chem. Eur. J.
(2013)et al.J. Am. Chem. Soc.
(1996)et al.Chem. Asian J.
(2007)et al.Eur. J. Org. Chem.
(2013)et al.Eur. J. Org. Chem.
(2013)et al.Org. Lett.
(2012)et al.J. Org. Chem.
(2011)et al.Tetrahedron Lett.
(2014)et al.Beilstein J. Org. Chem.
(2015)et al.Beilstein J. Org. Chem.
(2015)et al.Org. Lett.
(2010)et al.Eur. J. Org. Chem.
(2010)