The prefix for an
elementary reaction or some part thereof indicating that the bond(s) undergoing primitive changes form
part of a ring in the
transition state of the
elementary reaction. This prefix is used for nonpericyclic processes only and is replaced by '
cyclo' for pericyclic processes.
Source:
PAC, 1989, 61, 23
(System for symbolic representation of reaction mechanisms (Recommendations 1988))
on page 34