Search results

Search for "desymmetrization" in Full Text gives 52 result(s) in Beilstein Journal of Organic Chemistry.

Recent progress on the total synthesis of acetogenins from Annonaceae

  • Nianguang Li,
  • Zhihao Shi,
  • Yuping Tang,
  • Jianwei Chen and
  • Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

Graphical Abstract
  • conditions resulted in a smooth conversion of the starting material into THF 89. Triol (+)-90 was obtained with lipase Amano AK desymmetrization. For the appropriate side chain attachment, the termini were differentiated to give lactone (−)-91. Reduction of (−)-91 followed by a Wittig reaction yielded fully
  • controlled double cyclization of 230 allowed the selective formation of a single diastereomer 231 in one step, thus providing general access to annonaceous acetogenins containing trans/threo/trans or cis/threo/cis bis-THF core structures. Desymmetrization of diene 231 with AD-mix-β provided the known triol
PDF
Album
Review
Published 05 Dec 2008

Desymmetrization of 7-azabicycloalkenes by tandem olefin metathesis for the preparation of natural product scaffolds

  • Wolfgang Maison,
  • Marina Büchert and
  • Nina Deppermann

Beilstein J. Org. Chem. 2007, 3, No. 48, doi:10.1186/1860-5397-3-48

Graphical Abstract
  • product scaffolds and have also been used for ring opening of strained carbo- and heterocycles. In this paper we demonstrate the potential of these reactions for the desymmetrization of 7-azabicycloalkenes. Results We have established efficient protocols for the desymmetrization of different 7
  • -azabicycloalkenes by intra- and intermolecular tandem metathesis sequences with ruthenium based catalysts. Conclusion Desymmetrization of 7-azabicycloalkenes by olefin metathesis is an efficient process for the preparation of common natural product scaffolds such as pyrrolidines, indolizidines and isoindoles
  • ][57][58][59][60][61] In this paper, we describe the extension of this work and show that desymmetrization of 7-azabicycloalkenes via RORCM leads to valuable natural product scaffolds. In this context, symmetrical derivatives of 7-azabicycloalkenes like 7 and 12 are extremely interesting substrates for
PDF
Album
Supp Info
Full Research Paper
Published 18 Dec 2007
Other Beilstein-Institut Open Science Activities