| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject compound in remarkably high enantiomer selectivity and conversion by asymmetrically reducing a ketophantolactone in the presence of a transition metal complex containing a specific compound as a ligand. SOLUTION: This optically active pantolactone is produced by asymmetrically reducing ketopantolactone in the presence of a transition metal complex of 2,2'-bis(di-3,5-xylylphospholino)-5,5'-6,6',7,7',8,8'-octahydro-1,1'-b inaphthyl of formula I. The transition metal is preferably rhodium, ruthenium, iridium or palladium. The binaphthyl is obtained e.g. through processes comprising hydrogenating a 2,2'-dihalogeno-1,1'-binaphthy of formula II (X<1> is a halogen) in the presence of ruthenium-carbon catalyst, reacting the reaction product with metal magnesium, and subsequently condensing the obtained Grignard reagent with a di-3,5- xylylphosphinyl halide. |
