| 摘要 |
The present invention concerns a process for the preparation of a compound of formula I or a salt thereof (see formula I) characterised in that the process comprises a) epoxidation of a compound of formula 2 or a salt thereof (see formula II) in which formulae A is arylene; R1 is -C*R3R4R5; R2 is -O-alkyl, -O-cycloalkyl, -O-alkenyl, -O-aryl, -O-aralkyl, -O-aralkoxyalkyl, -O-alkylsulfonyl, -O-arylsulfonyl, chlorine, bromine or iodine; R3 is hydrogen; R4 is aryl; R5 is alkyl, cycloalkyl, aryl, alkoxyalkyl or hydroxyalkyl; and, wherein C* is an asymmetric carbon atom; b) optionally followed by isolation of the desired stereoisomer. |
