A Facile Synthesis of Isochromenes Based on Reactions of 2-Lithio-β-methoxystyrenes with Carbonyl Compounds

 

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Abstract

The reactions of α-substituted 2-lithio-β-methoxystyrenes, generated in situ by bromine-lithium exchange between α-substituted 2-bromo-β-methoxystyrenes and butyllithium in diethyl ether at 0 °C, with carbonyl compounds afforded α-substituted 2-(β-methoxyvinyl)benzyl alcohols, which were treated with a catalytic amount of concentrated hydriodic acid to give 4-substituted iso­chromenes (1H-2-benzopyrans) in reasonable yields.

References

• 1 Kobayashi K. Hayashi K. Miyamoto K. Morikawa O. Konishi H. Synthesis  2006,  2934 
  Article in Thieme ConnectGoogle Scholar
• 2 Yao X. Li C.-J. Org. Lett.  2006,  8:  1953 
  CrossrefPubMedGoogle Scholar
• 3 For an example, see: Wei W.-G. Zhang Y.-X. Yao Z.-J. Tetrahedron  2005,  61:  11882 
  CrossrefGoogle Scholar
• For recent reports on the synthesis of isochromene derivatives, see:
• 4a Yue D. Cà ND. Larock RC. Org. Lett.  2004,  6:  1581 
  CrossrefGoogle Scholar
• 4b Li X. Chianese AR. Vogel T. Crabtree RH. Org. Lett.  2005,  7:  5437 
  CrossrefGoogle Scholar
• 4c Patil NT. Pahadi NK. Yamamoto Y. J. Org. Chem.  2005,  70:  10096 
  CrossrefGoogle Scholar
• 4d Asao N. Chan CS. Takahashi K. Yamamoto Y. Tetrahedron  2005,  61:  11323 
  CrossrefGoogle Scholar
• 4e Parthasarsthy K. Jeganmohan M. Cheng C.-H. Org. Lett.  2006,  8:  621 
  CrossrefGoogle Scholar
• 4f Kusama H. Sawada T. Okita A. Shiozawa F. Iwasawa N. Org. Lett.  2006,  8:  1077 
  CrossrefGoogle Scholar
• 4g Yue D. Cà ND. Larock RC. J. Org. Chem.  2006,  71:  3381 
  CrossrefGoogle Scholar
• 4h Pedrosa R. Sayalero S. Vicente M. Eur. J. Org. Chem.  2006,  5110 
  CrossrefGoogle Scholar
• 4i Villeneuve K. Eur. J. Org. Chem.  2006,  5449 
  CrossrefGoogle Scholar
• 4j Tam W. Barluenga J. Vázquez-Villa H. Merino I. Ballesteros A. González JM. Chem. Eur. J.  2006,  12:  5790 
  CrossrefGoogle Scholar
• 5 Wünsch B. Höfner G. Bauschke G. Arch. Pharm.  1993,  326:  513 
  CrossrefGoogle Scholar