title: Resolution of carboxylic acids using copper(I)-promoted removal of propargylic esters under neutral conditions.
abstract: A method for the optical resolution of carboxylic acids is described. Condensation of racemic carboxylic acids with chiral terminal propargyl alcohols gave separable diastereomeric esters. Chromatographic separation followed by heating the individual diastereomers in methanol with catalytic copper(I) halide regenerated the carboxylic acids in good yields and in enantiomeric ratios of ≥94%. This method is particularly useful for the resolution of carboxylic acids that are incompatible with conventional ester hydrolysis.
authors.affiliation: Chemical Methodologies and Library Development Center, 2034 Becker Drive, University of Kansas, Lawrence, Kansas 66047-3761, United States.
authors.forename: Partha
authors.initials: P
authors.lastname: Ghosh
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Aubé
mesh_terms: D000480:Alkynes / Q000737:chemistry* / Q000302:isolation & purification*; D002264:Carboxylic Acids / Q000737:chemistry*; D002845:Chromatography; D003300:Copper / Q000737:chemistry*; D004952:Esters; D006863:Hydrogen-Ion Concentration; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D002264:Carboxylic Acids; D004952:Esters; D003300:Copper