Chlorination of enantiomerically pure 1,1′-bis(hydroxyalkyl)-3,3′-biindolizines: conservation of chirality by thermal treatment

Abstract

Enantiomerically pure 1,1′-bis(hydroxyalkyl)-3,3′-biindolizines 1 racemize unexpectedly by reaction with tetra-chloromethane–triphenylphosphine at room temperature affording the corresponding dichloro compounds 2, whereas the chirality is preserved at higher reaction temperatures.