quasi-enantiomers

https://doi.org/10.1351/goldbook.Q04997
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.
Source:
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2215 [Terms] [Paper]