Tetrabutylammonium tribromide (TBATB): a mild and efficient catalyst for O-isopropylidenation of carbohydrates

A wide range of O-isopropylidene derivatives can be prepared from the sugars and their derivatives on reaction with acetone at room temperature by employing 2 mol % of tetrabutylammonium tribromide (TBATB) as a catalyst. Good yields, low catalyst loading, mild reaction conditions, and a non-aqueous workup procedure are some major advantages of this protocol.