Abstract
Epimeric mixtures of 1-β-hydroxya1kyl zirid1ne-il-carboxy1ic esters were prepared by the Gabriel-Cromwell reaction, followed by their separation by liquid chromatography with subsequent lactonization of each epimer in the presence of base to give pure enantiomers and diastereomers of lactones differing as to the aziridine (C-2) carbon configuration. According to PMR spectroscopy data, twisted boat is the most preferred six-membered cycle configuration in 4-oxa-1-azabicyc1o[4.1,0]- heptane-J-ones in solution. The absolute configurations of carbon atoms in chiral lactones were determined by CD-spectroscopy. Epimers of 1-β-hydroxyalkylaziridine- 2-carboxylic esters sharing the same carbon configuration (α-substituent at nitrogen) but differing in C-2 configuration undergo lactonization at different rate. A rational explanation of this phenomenon is provided
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call