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Synthesis 2008(21): 3383-3388  
DOI: 10.1055/s-0028-1083167
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Asymmetric Diels-Alder Reactions of Sulfonyl-Functionalized α,β-Unsaturated Ketones with Cyclopentadiene Catalyzed by Chiral Lewis Acid

Wen Pei*, Yu-Guang Wang, Yong-Jiang Wang, Li Sun
College of Chemical Engineering and Materials, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. of China
Fax: +86(571)88320629; e-Mail: peiwen58@zjut.edu.cn;
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Publication History

Received 7 May 2008
Publication Date:
16 October 2008 (online)

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Abstract

Asymmetric Diels-Alder reactions of (E)-1-substituted sulfonyl-3-penten- 2-ones with cyclopentadiene catalyzed by a chiral titanium reagent were investigated. The enantioselectivity was studied with different substituents in the position of sulfonyl moiety. 6-Methyl-5-(substituted-sulfonylacetyl)bicyclo[2.2.1]hept-2-enes (4) were prepared in high yield with high optical purity. The absolute configuration of the cycloadducts was determined by an alternative synthetic route to compound 4, which was prepared by an asymmetric Diels-Alder reaction of the acyloxazolidinone 6 with cyclopentadiene, followed by nucleophilic addition of substituted sulfonylmethyl lithium to the product. Crystals of (5R,6S)-6-methyl-5-(phenylsulfonylacetyl)bicyclo-[2.2.1]hept-2-ene (4a) with >99% ee was prepared and studied. A mechanism of asymmetric reaction of sulfonyl-functionalized α,β-unsaturated ketone with cyclopentadiene is presented.

Key words

sulfonyl unsaturated ketone - Diels-Alder reaction - chiral Lewis acid - asymmetric catalyst - crystal - mechanism

    References

  • 1a Evans DA. Chapman KT. Bisaha J. J. Am. Chem. Soc.  1988,  110:  1238 
    Google Scholar
  • 1b Kagan HB. Riant O. Chem. Rev.  1992,  92:  1007 
    Google Scholar
  • 1c Takao KI. Munakata R. Tadano K. Chem. Rev.  2005,  105:  4779 
    Google Scholar
  • 2a Wada E. Yasuoka H. Pei W. Chin U. Kanemasa S. Engineering Sciences Reports, Kyushu University  1995,  17:  353 
    Google Scholar
  • 2b Wada E. Pei W. Yasuoka H. Chin U. Kanemasa S. Tetrahedron  1996,  52:  1205 
    Google Scholar
  • 3a Wada E. Pei W. Kanemasa S. Chem. Lett.  1994,  2345 
    Google Scholar
  • 3b Pei W. Wada E. Kanemasa S. Chin. Chem. Lett.  1997,  8:  935 
    Google Scholar
  • 3c Pei W. Chem. J. Chin. Univ.  1998,  19:  402 
    Google Scholar
  • 3d Pei W. Deng Q. Wang HB. Sun L. Chin. J. Org. Chem.  2006,  26:  727 
    Google Scholar
  • 4 Pei W. Shao YS. Sun L. Acta Crystallogr., Sect. E  2004,  60:  374 
    CrossrefGoogle Scholar
  • 5 Pei W. Wang YJ. Sun MZ. Xiong XB. Yu CQ. Acta Crystallogr., Sect. E: Struct. Rep. Online  2007,  63:  2142 
    Google Scholar
  • 6 Narasaka K. Iwasawa N. Inoue M. Yamada T. Nakashima M. Sugimori J. J. Am. Chem. Soc.  1989,  111:  5340 
    CrossrefGoogle Scholar
  • 7 Smith AB. Hale KJ. Mccauley JP. Tetrahedron Lett.  1989,  30:  5579 
    CrossrefGoogle Scholar