Diarylprolinol in the direct asymmetric aldol reaction of trifluoromethylacetaldehyde ethyl hemiacetal with aldehyde

Asymmetric direct aldol reaction of trifluoromethylacetaldehyde with aldehyde using diarylprolinol as a catalyst, to afford a synthetically useful β-trifluoromethyl-β-hydroxy aldehyde with excellent enantioselectivity, was developed. Commercially available trifluoromethylacetaldehyde ethyl hemiacetal was used directly as a precursor of trifluoromethylacetaldehyde without acid pyrolysis or distillation prior to use.