peracetylated

Peracetylated refers to a molecule in which all free hydroxyl (and sometimes amino) groups have been converted to acetate esters. This term is commonly used in carbohydrate chemistry and related fields to describe fully acetylated derivatives, such as sugars, nucleosides, and cellulose-based materials. Peracetylation increases lipophilicity, reduces polarity, and can improve crystallization and stability, aiding purification and analysis.

Synthesis typically involves treating the target compound with acetic anhydride, often in a base such as pyridine or in the presence of a catalyst like 4-dimethylaminopyridine (DMAP). Reaction conditions are chosen to favor complete acetylation of all available reactive sites, producing a peracetylated derivative. Depending on the substrate, peracetylation may also protect exocyclic amines or other functional groups during subsequent transformations.

Peracetylated compounds have several practical uses. In carbohydrate synthesis, they serve as versatile protecting groups that mask multiple hydroxyls, allowing selective modification at specific positions. Peracetylated sugars and nucleosides can be converted back to the parent compounds by deprotection. In analytical contexts, peracetylation can improve volatility for certain chromatography or mass spectrometry workflows. In materials science, partially or fully acetylated cellulose derivatives (such as cellulose acetate) are important for films and fibers.

Deprotection is typically achieved by hydrolysis under basic conditions or methanolysis, regenerating the original hydroxyl groups. Safety considerations include the handling of acetic anhydride and the exothermic nature of acetylation reactions.