The enantiomers of the inhalation anesthetic agent, isoflurane (1-chlo
ro-2,2,2-trifluoroethyl difluoromethyl ether), are prepared by a synth
esis starting from 2,2,2-trifluoroethanol. (R)-(+)-Dehydroabietylamine
is used as the resolving agent for the racemic acid intermediate 1. T
he optical purities of both (S)-(+)- and (R)-(-)-isofluranes are deter
mined to be >99% ee (enantiomeric excess) by chiral capillary gas chro
matography.