Abstract A clean, facile and practical synthesis of α-oxoketene S, S-acetals in water has been developed. Catalyzed by tetrabutylammonium bromide (TBAB) at room temperature in water, a range of β-dicarbonyl compounds have been converted to the corresponding α- oxoketene S, S-acetals in very high yields. The catalyst in the aqueous phase can be recycled after the separation of organic products.
