Asymmetric Diels-Alder reactions of chiral (E)-2-cyanocinnamates II. Synthesis of the four 1-amino-2-phenyl-1-cyclohexanecarboxylic acids in enantiomerically pure form

  1. Cativiela, C. 2
  2. Avenoza, A. 1
  3. Paris, M. 2
  4. Peregrina, J.M. 1
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Instituto de Nanociencia y Materiales de Aragón
    info

    Instituto de Nanociencia y Materiales de Aragón

    Zaragoza, España

    ROR https://ror.org/031n2c920

Journal:
Journal of Organic Chemistry

ISSN: 0022-3263

Year of publication: 1994

Volume: 59

Issue: 25

Pages: 7774-7778

Type: Article

DOI: 10.1021/JO00104A038 SCOPUS: 2-s2.0-0028568258 WoS: WOS:A1994PY82400038 GOOGLE SCHOLAR

More publications in: Journal of Organic Chemistry

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Abstract

High and complementary diastereoselectivities were obtained in the asymmetric Diels-Alder reactions of chiral (E)-2-cyanocinnamates with butadiene when (S)-ethyl lactate and (R)-pantolactone were used as chiral auxiliaries in the presence of TiCl4. The most selective reactions allowed the synthesis of the cycloadducts 2a and 3b, whose absolute configurations were assigned by an X-ray diffraction study of diastereoisomer 3b. The hydrolysis and subsequent hydrogenation of the stereoisomers gave the corresponding enantiomeric cyanocarboxylic acids. From these products the four 1-amino-2-phenyl-1-cyclohexanecarboxylic acids were synthesized in enantiomerically pure form following a protocol with stereocontrolled and stereodivergent transformations.