Constitutionally different yet closely related chemical species MX and MY having the opposite chirality sense of the large common chiral moiety M. For example (
R)-2-bromobutane is a quasi-enantiomer of (
S)-2-chlorobutane.
See also: quasi-racemic compound
Source:
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2215 (https://doi.org/10.1351/pac199668122193)