189013-32-9Relevant academic research and scientific papers
A unified asymmetric approach to substituted hexahydroazepine and 7-azabicyclo[2.2.1]heptane ring systems from D(-)-quinic acid: Application to the formal syntheses of (-)-balanol and (-)-epibatidine
Albertini, Enrichetta,Barco, Achille,Benetti, Simonetta,De Risi, Carmela,Pollini, Gian P.,Zanirato, Vinicio
, p. 17177 - 17194 (2007/10/03)
3,4-O-Isopropylidene-3(R),4(S)-dihydroxycyclohexanone 7, a chiron easily prepared through a five step sequence from D(-)-quinic acid 1, has been efficiently utilized as the starting building block for the enantioselective syntheses of (3R,4S)-N-p-toluenesulfonyl-3,4-epoxy-hexahydroazepine 17 and (1R,4S)-N-tert-butoxycabonyl-7-azabicyclo[2.2.1]heptan-2-one 43, advanced intermediates already taken to (-)-balanol and (-)-epibatidine respectively. While the nitrogen atom ring insertion via Beckmann rearrangement was the key step for the construction of the hexahydroazepine ring of 17, a regio- and stereospecific intramolecular nucleophilic ring opening of an intermediate cyclic sulfate featured the approach to the substituted 7-azabicyclo[2.2.1]heptane nucleus of 43.
Total Synhesis of Balanol, Part 1. Enantioselective Synthesis of the Hexahydroazepine Ring via Chiral Epoxides and Azidirines
Tanner, David,Almario, Antonio,Hoegberg, Thomas
, p. 6061 - 6070 (2007/10/02)
Three differents routes to the hexahydroazepine unit of the natural products balanol (1) and ophicordin (2) are described.The common starting material is the chiral epoxy alcohol 3 which is converted to the balanol degradation product 10 (Scheme 1) or to
