• Media type: E-Article
  • Title: Synthesis of a Novel Enantiopure Spiro‐B‐norestradiol Analogue by Multiple Pd‐Catalyzed Transformations
  • Contributor: Tietze, Lutz F.; Wiegand, J. Matthias; Vock, Carsten A.
  • imprint: Wiley, 2004
  • Published in: European Journal of Organic Chemistry
  • Language: English
  • DOI: 10.1002/ejoc.200400263
  • ISSN: 1434-193X; 1099-0690
  • Keywords: Organic Chemistry ; Physical and Theoretical Chemistry
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title><jats:p>The novel tetracyclic spiro compound <jats:bold>13</jats:bold> was synthesized by the use of two subsequent Pd‐catalyzed reactions. Firstly, the <jats:italic>ortho</jats:italic>‐bromobenzyl chloride <jats:bold>1</jats:bold> was coupled with the enantiopure boronic ester <jats:bold>8</jats:bold>, obtained from the Hajos−Wiechert ketone in a chemoselective Suzuki‐type reaction to give <jats:bold>12</jats:bold> in 77% yield. Unexpectedly, the intramolecular Heck reaction then did not provide the annulated compound <jats:bold>6</jats:bold>, but the spirocyclic compound <jats:bold>13</jats:bold>, containing a quaternary carbon center, in 73% yield. The Heck reaction was also performed under microwave irradiation conditions, allowing a considerably shorter reaction time. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2004)</jats:p>