4-Trifluoromethoxy proline: synthesis of stereoisomers and lipophilicity study.

All four stereoisomers of 4-CF 3 O-proline have been synthesized through a fluorodesulfurization approach using the corresponding 4-hydroxyprolines as starting materials. The investigation of their lipophilicity characteristics and comparison with those of other 4-substituted proline analogs demonstrated a similar impact of CF 3 and CF 3 O groups on log  D .