摘要 |
<p>Compounds of formula (I) or (Ia): <CHEM> where R is 5-indanyl or a carboxylic acid protecting group, or an amine salt thereof, are prepared by hydrogenating an (E)-allylic ether of formula (II) or (IIa): <CHEM> in the presence of a stereoselective rhodium or ruthenium biphosphine catalyst and a protic solvent.</p> |