Straightforward Synthesis of (<i>S</i>)- and (<i>R</i>)-α-Trifluoromethyl Proline from Chiral Oxazolidines Derived from Ethyl Trifluoropyruvate
作者:Grégory Chaume、Marie-Céline Van Severen、Sinisa Marinkovic、Thierry Brigaud
DOI:10.1021/ol062593+
日期:2006.12.1
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
Concise access to enantiopure (S)- and (R)-α-trifluoromethyl pyroglutamic acids from ethyl trifluoropyruvate-based chiral CF3-oxazolidines (Fox)
作者:Grégory Chaume、Marie-Céline Van Severen、Louis Ricard、Thierry Brigaud
DOI:10.1016/j.jfluchem.2008.07.019
日期:2008.11
A straightforward synthesis of enantiopure (S)- and (R)-α-Tfm-pyroglutamic acid is reported. The strategy is based on the use of a chiral CF3-hydroxymorpholinone intermediate conveniently obtained from ethyl trifluoropyruvate-based chiral CF3-oxazolidines (Fox). The key step is an oxidative cyclization followed by a reductive cleavage of the (R)-phenylglycinol chiral auxiliary.