PROCESS FOR THE DE-ENRICHMENT OF ENANTIOMERICALLY ENRICHED SUBSTRATES

摘要

There is provided a process for the de-enrichment of enantiomerically enriched compositions which comprises reacting an enantiomerically enriched composition comprising at least a first enantiomer or diastereomer of a substrate comprising a carbon-heteroatom bond, wherein the carbon is a chiral centre and the heteroatom is a group VI heteroatom, in the presence of a catalyst system and optionally a reaction promoter to give a product composition comprising first and second enantiomers or diastereomers of the substrate having a carbon-heteroatom bond, the ratio of second to first enantiomer or disatereomer in the product composition being greater than the ratio of second to first enantiomer or disatereomer in the enantiomerically enriched composition. Preferred substrates include compounds of Formula (1) wherein: X represents O, S; R¹, R² each independently represents an optionally substituted hydrocarbyl, a perhalogenated hydrocarbyl, an optionally substituted heterocyclyl group; or R¹ & R² are optionally linked in such a way as to form an optionally substituted ring(s); provided that R¹ and R²are selected such that * is a chiral centre. In a preferred process a compound of Formula : (2) wherein: X represents O, S; R¹, R² each independently represents an optionally substituted hydrocarbyl, a perhalogenated hydrocarbyl, an optionally substituted heterocyclyl group; or R¹ & R² are optionally linked in such a way as to form an optionally substituted ring(s); provided that R1 and R2 are different, may be obtained.