Abstract: The present invention provides a method for chiral resolution of Trolox. The present disclosure relates to a method for producing a solid salt of a compound of formula I, wherein an amide-based solvent is added to a sample, which contains a compound of formula I, while being assumed to contain a compound of formula II, in the presence of an optical resolution agent: Formula I: (R)-6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (hereinafter referred to R Trolox) Formula II: (S)-6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (hereinafter referred to S Trolox).

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-(?)-flocinopiperidol is thereby produced with surprisingly high selectivity.