RXNO: reaction ontologies
RXNO is the name reaction ontology. It contains more than 500 classes representing organic reactions such as the Diels–Alder cyclization.
MOP is the molecular process ontology. It contains the underlying molecular processes, for example cyclization, methylation and demethylation.
Both ontologies are stored as .obo and .owl files, both of which can be read by Protege (http://protege.stanford.edu/).