Formation of O-Allyl Oximes by Reaction of Allylzinc Reagents with α-Chloronitroso Compounds

Abstract

The reaction of α-chloronitrosocyclohexane with allyl­zinc reagents in THF selectively provides O-allylcyclohexanone oximes in very good yields in an ene type reaction followed by zinc halide elimination. N-Allyl hydroxylamines are formed as minor products via N-allyl nitrones when a nonpolar solvent, e.g. toluene, is employed. In both cases complete allylic transposition with respect to the allylic organozinc reagent is observed. Compared to non-metalated allyl compounds, which give N-allyl nitrones upon reaction with α-chloronitroso compounds, the use of zinc as hydrogen equivalent in an ene type reaction displays a drastic change of reactivity.

Key words

ene reactions - regioselectivity - zinc - allylations - organometallic reagents

References

• 2 Adam W. Krebs O. Chem. Rev.  2003,  103:  4131 
• 3a Leach AG. Houk KN. J. Am. Chem. Soc.  2002,  124:  14820 
• 3b Leach AG. Houk KN. Chem. Commun.  2002,  1243 
• 3c Leach AG. Houk KN. Org. Biomol. Chem.  2003,  1:  1389 
• 3d Lu X. Org. Lett.  2004,  6:  2813 
• 4 Banks RE. Barlow MG. Haszeldine RN. J. Chem. Soc.  1965,  4714 
• 5a Schenk C. de Boer TJ. Tetrahedron  1979,  35:  147 
• 5b Schenk C. de Boer TJ. Recl. Trav. Chim. Pays-Bas  1979,  98:  18 
• 6 Kresze G. Vasella A. Felber H. Ritter A. Ascherl B. Recl. Trav. Chim. Pays-Bas  1986,  105:  295 
• 7a Oppolzer W. Tamura O. Sundarababu G. Signer M. J. Am. Chem. Soc.  1992,  114:  5900 
• 7b Oppolzer W. Tamura O. Deerberg J. Helv. Chim. Acta  1992,  75:  1965 
• 8 Oppolzer W. Angew. Chem., Int. Ed. Engl.  1989,  28:  38 ; Angew. Chem. 1989, 101, 39
• 9a Cai J. Davies AG. J. Chem. Soc., Perkin Trans. 2  1992,  1743 
• 9b Dang H.-S. Davies AG. J. Organomet. Chem.  1992,  430:  287 
• 9c Davies AG. J. Chem. Soc., Perkin Trans. 1  2000,  1997 
• 9d Dang H.-S. Davies AG. J. Organomet. Chem.  1998,  553:  67 
• 10 Aston JG. Menard DF. J. Am. Chem. Soc.  1935,  57:  1920 
• 11 Miyabe H. Matsumura A. Yoshida K. Yamauchi M. Takemoto Y. Synlett  2004,  2123 
• 12a Schenk C. Beekes ML. de Boer TJ. Recl. Trav. Chim. Pays-Bas  1980,  99:  246 
• 12b Schenk C. Beekes ML. van der Drift JAM. de Boer TJ. Recl. Trav. Chim. Pays-Bas  1980,  99:  278 
• 12c Schenk C. de Boer TJ. Tetrahedron  1980,  36:  1843 
• 13 Barbot F. Miginiac P. Bull. Soc. Chim. Fr.  1977,  1-2:  113 
• 14 Erdik E. Organozinc Reagents in Organic Synthesis   CRC Press; Boca Raton, FL: 1996.  p.147 
• 15 Rieke RD. Aldrichimica Acta  2000,  33:  52 
• 16 Diekmann H. Luettke W. Angew. Chem.  1968,  80:  395 
• 17 Original Procedure: Guziek FS. Russo JM. Synthesis  1984,  479 
• 17Modified Conditions (Scheme 8): i) HONH₂·HCl, NaOAc, MeOH, reflux, 3 days; ii) t-BuOCl, CH₂Cl₂, 0 °C, 1.5 h.
• 18 Müller E. Metzger H. Fries D. Chem. Ber.  1954,  87:  1449 

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