Straightforward synthesis of (S)- and (R)-alpha-trifluoromethyl proline from chiral oxazolidines derived from ethyl trifluoropyruvate.
[Structure: see text] A concise synthesis of both enantiomers of alpha-Tfm-proline and (S)-alpha-Tfm-prolinol from ethyl trifluoropyruvate is reported. The key step is a diastereoselective allylation reaction of ethyl trifluoropyruvate and (R)-phenylglycinol-based oxazolidines or imine. The lactone obtained by cyclization of the resulting hydroxy ester proved to be a valuable intermediate for the synthesis of (S)-alpha-Tfm-allylglycine and (S)-alpha-Tfm-norvaline in enantiopure form.
Chaume
Grégory
G
Laboratoire Synthèse Organique Sélective et Chimie Organométallique (SOSCO), UMR CNRS 8123, Université de Cergy-Pontoise, 5, Mail Gay-Lussac-Neuville sur Oise 95031, Cergy-Pontoise Cedex, France.
Van Severen
Marie-Céline
MC
Marinkovic
Sinisa
S
Brigaud
Thierry
T