Cyclohexylamine → (R)-2-[2-(tert-butoxy)-2-oxoethyl]-5-phenylpentanoic acid

Participants

Reaction Steps

A stirred solution of (E)-2-[2-(tert-butoxy)-2-oxoethyl]-5-phenyl-2-pentenoic acid (100 g, 0.34 mol), cyclohexylamine (39 ml, 0.34 mol) and [(S)-2,2′-bis(diphenylphosphino-1,1′-binaphthyl]chloro(p-cymene)ruthenium chloride (0.64 g, 0.69 mmol) in methanol (100 ml) was heated to 60° C, under hydrogen (60 p.s.i.), for 42 hours and then allowed to cool to room temperature. The mixture was filtered through celite and then concentrated in vacuo to a yellow solid which was purified by re-crystallisation from acetone (850 ml). The resulting solid was partitioned between ethyl acetate (1200 ml) and citric acid solution (10%, 1200 ml) and the organic phase was separated, washed with demineralised water (1200 ml) and concentrated in vacuo to leave the title compound as an oil (80 g).

Provenance & Evidence