Tetraacetyl diborate is an organoboron compound with the molecular formula (CH3COO)2BOB(CH3COO)2.

It is not well known and was discovered accidentally by an attempt trying to make boron triacetate in the 1950s.

It was made by reacting boric acid and acetic anhydride around 75 °C (167 °F) under nitrogen which created tetraacetyl diborate and acetic acid.

It crystallized as a colorless solid.

[1] Tetraacetyl diborate reacts with methanol to form water and diacetyl methoxyboron.