Sodium Bicarbonate → (r)-2-[2-(Tert-butoxy)-2-oxoethyl]-5-phenylpentanoic acid sodium salt

Participants

Reaction Conditions

Reaction Steps

A stirred solution of sodium bicarbonate (28.6 g, 0.34 mol), (E)-2-[2-(tert-butoxy)-2-oxoethyl]-5-phenyl-2-pentenoic acid (100 g, 0.34 mol) and [(S)-2,2′-bis(diphenylphosphino-1,1′-binaphthyl]chloro(p-cymene)ruthenium chloride (0.63 g, 0.68 mmol) in methanol (750 ml) and water (250 ml) was heated to 60° C., under hydrogen (60 p.s.i.), for 24 hours and then allowed to cool to 20-25° C. (enantiomeric excess 87%). The mixture was filtered through a filter aid Celite® and the solvent was stripped and replaced with acetonitrile by distillation at atmospheric pressure, at a constant volume of 500 ml. The resulting suspension was cooled to 20-25° C. and was stirred for 24 hours, then filtered. The residue was washed with acetonitrile (3×25 ml) and then dried in vacuo at 45° C. for 3 hours to leave the title compound as a colourless solid (65 g, 61% yield, enantiomeric excess=94.3%, 95% pure by NMR).

Provenance & Evidence