Synthesis of α,α-difluoro-β-hydroxy ketone via the La(OTf)3-catalyzed aldol reaction of carbonyl compounds with difluoroenol O-Boc esters

We herein present an efficient method for the construction of α,α-difluoro-β-hydroxy ketones. The La(OTf)3-catalyzed aldol reaction between difluoroenol O-Boc (Boc = tert-butyloxycarbonyl) esters and carbonyl compounds affords α,α-difluoro-β-hydroxy ketones in good yield. The key reagents of this reaction are the difluoroenol O-Boc esters, which are easily synthesized from trifluoromethyl alcohols in two steps.