(R)-beta-aminophenethyl alcohol → (S)-1-[4-(3-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid

Participants

Reaction Steps

The salt of the (S)-(II) compound with (R)-(−)-2-phenylglycinol was prepared in an analogous manner as described in Example 2a) from rac-1-[4-(3-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid (5 g, 15.2 mmol) in acetonitrile/water 95:5 (50 mL) using a solution of only 1.46 g (R)-(−)-2-phenylglycinol (10.6 mmol, 0.7 eq) in acetonitrile/water 95:5 (3.3 mL). From the salt (3.2 g, 45% based on racemic acid) obtained in 99.7:0.3 diastereomeric ratio the (S)-(II) compound was liberated and purified in a similar manner as described in Example 2b) to afford (S)-1-[4-(3-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid (2.21 g, 44% based on racemic acid) in high purity (HPLC: 99.4% area) and with >99.9:0.1% er.

Provenance & Evidence