PROCESS AND INTERMEDIATES FOR PREPARING INDANYLOXYDIHYDROBENZOFURANYL ACETIC ACID DERIVATIVES AS GPR40 AGONISTS

摘要

The present invention relates to compounds of formula I wherein RS denotes F or CF3, Ra denotes H or C1-4-alkyl and Z denotes a leaving group or an optionally substituted or protected hydroxyl group, suitable as intermediates in the synthesis of indanyloxydihydrobenzofuranylacetic acids, which are GPR40 agonists, to a process for preparing these intermediates and to the process for preparing the GPR40 agonists making use of an asymmetric catalytic hydrogenation reaction in the presence of a transition metal catalyst and a chiral auxiliary.