444313-68-2Relevant articles and documents
Stereoselective synthesis of (1R,4R)-N-acyl-2-oxa-5-aza-bicyclo[2.2.1]heptan-3-ones via mesoionic compounds. An improved synthesis of cis-4-hydroxy-D-proline
Dalla Croce, Piero,La Rosa, Concetta
, p. 197 - 201 (2002)
We report an asymmetric synthesis of (1R,4R)-N-acyl-2-oxa-5-aza-bicyclo[2.2.1]heptan-3-ones, starting from the inexpensive and commercially available trans-4-hydroxy-L-proline and achieved by treating N-acyl-trans-4-hydroxy-L-prolines with acetic anhydride. The formation of intermediate mesoionic compounds may explain the formation of N-acyl-2-oxa-5-aza-bicyclo[2.2.1]heptan-3-ones with (R)-absolute configuration at C(4). Acidic cleavage of these lactones readily affords N-acyl-cis-4-hydroxy-D-prolines or cis-4-hydroxy-D-proline in good yields.
A concise formal synthesis of unnatural (+)-aphanorphine from (2S,4R)-4-hydroxyproline
Ma, Zhiqiang,Zhai, Hongbin
, p. 161 - 163 (2008/03/13)
(-)-Aphanorphine methyl ether was synthesized in ten steps from commercially available (2S,4R)-4-hydroxyproline, featuring the C-2 configuration inversion of an intermediate amide and intramolecular Friedel-Crafts reaction. The present work constitutes a
