| abstract |
The present invention provides a method in which when using (+)-dibenzoyl-D-tartaric acid to optically divide (±)-1-methyl-4-(2,4,6-trimethoxyphenyl)-3-piperidinone, an ether-based solvent is added and an extremely high yield of (R)-1-methyl-4-(2,4,6-trimethoxyphenyl)-3-piperidinone (+)-dibenzoyl-D-tartrate is thereby obtained, a slurry thereof is treated with a base, a "three-dimensionally bulky reducing agent" is subsequently used, and cis-(-)-fluocino piperidol is thereby produced with surprisingly high selectivity. |