| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject new compound useful as a chiral ligand in an asymmetric synthetic reaction. SOLUTION: This compound is shown by formula I [*mark is an optically active carbon atom; X is a hydrogen atom or a group of the formula COR (R is a group of formula II; in the formula II, Ar is a (substituted) 6-10C aromatic ring; R' is a 1-4C alkyl)]. The compound is obtained by reacting a racemic threo-1,2-bis(pentafluorophenyl)ethane 1,2diol with a carboxylic acid of formula III in the presence of both a condensation agent (e.g. dicyclohexylcarbodiimide) and a catalyst (e.g. dimethylaminopyridine). An optically active threomonoesters of formula IV or an optically active threodiesters of formula V in the compound of formula I are hydrolyzed to give an optically active threo-1,2-bis(pentafluorophenyl)ethane-1,2-diol of formula VI. The diol compound can be expected to have more excellent asymmetry recognition ability as an asymmetric ligand than a known compound by strong intermolecular interaction by high electron density on a benzene ring. |
