The enzyme <small>L</small>rhamnonate dehydratase () catalyzes the chemical reaction
This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is <small>L</small>-rhamnonate hydro-lyase (2-dehydro-3-deoxy-<small>L</small>-rhamnonate-forming). This enzyme is also called <small>L</small>rhamnonate hydro-lyase. This enzyme participates in fructose and mannose metabolism.
As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes , , , and .