Practical synthesis of fluorous oxazolidinone chiral auxiliaries from alpha-amino acids.
[reaction: see text] A series of new fluorous-supported oxazolidinone chiral auxiliaries has been prepared using a versatile and general five-step pathway, starting from readily available chiral alpha-amino acids. The key feature of this synthesis is the efficient generation of a suitably active perfluoroalkyllithium species. By use of this protocol, the auxiliaries can be obtained in high enantiomeric purity and on multigram scales from L-phenylalanine and L-valine with overall yields as high as 55%. The new methodology also incorporates fluorous solid-phase extraction on the large scale, allowing bulk quantities (up to 25 g) of fluorous compounds to be purified from the crude reaction mixture.
Hein
Jason E
JE
Department of Chemistry, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
Geary
Laina M
LM
Jaworski
Ashley A
AA
Hultin
Philip G
PG
D000596:Amino Acids / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D023303:Oxazolidinones / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000596:Amino Acids; D006845:Hydrocarbons, Fluorinated; D023303:Oxazolidinones