Caesium acetate

Caesium acetate or cesium acetate is an ionic caesium compound with the molecular formula CH₃COOCs. It is a white solid that may be formed by the reaction of caesium hydroxide or caesium carbonate with acetic acid.

It is used in organic synthesis. One example is in the Perkin synthesis: the formation of unsaturated cinnamic-type acids by the condensation of aromatic aldehydes with fatty acids. Replacement of the commonly used sodium acetate with caesium acetate has been shown to improve yields by up to 10 times.

It is often used to invert secondary alcohols. After converting the alcohol to a good leaving group, such as a mesylate, direct S_N2 substitution with the acetate produces the O-acetate with inverted stereochemistry, which can be converted back to a hydroxyl group.

Caesium acetate is occasionally used instead of caesium formate in petroleum drilling fluids.^{[citation needed]}