With the enantioselective intramolecular benzoin reaction established as a synthetic tool, and in combination with our efforts in the synthesis of bioactive natural products bearing a quaternary α-hydroxy ketone unit, [18] such as the 4-chromanone derivative (S)-eucomol [19] (4), we herein report our studies on the catalytic asymmetric synthesis of various 3-hydroxy-4-chromanones brought about by the chiral triazolium salts 1-3 as pre-catalysts (Figure [1] ).
