Process for the preparation of an enantiomer of trans-(+-)-methyl (2R 3S)-2 3-epoxy-3-(4-methoxyphenyl) propionate by preferential crystallization

摘要

Process for the preparation of methyl (-)-(2R,3S)-2,3-epoxy-3-(4-methoxyphenyl)propionate, characterised in that a solution of a mixture of enantiomers of trans methyl (+/-)-2,3-epoxy-3-(4-methoxyphenyl)propionate, rich in laevorotatory enantiomer, is prepared first of all and then a crystal seed of laevorotatory enantiomer is then added to the solution, which is allowed to crystallise, and the crystals formed are isolated.