Citric Acid → 5(S)-(Boc-amino)-4(S)-hydroxy-6-phenyl-2(R)-(o-fluorophenylmethyl)-hexanoic acid

Participants

Reaction Steps

Analogously to Example 1i), 4.5 g (10.8 mmol) of 5(S)-[1(S)-(Boc-amino)-2-phenylethyl]-3(R)-(o-fluorophenylmethyl)-dihydrofuran-2-(3H)-one in 170 ml of dimethoxyethane are hydrolysed with 43.5 ml of 1M lithium hydroxide solution. The evaporation residue of the reaction mixture is poured onto a mixture of ice, 120 ml of sat. ammonium chloride solution and 240 ml of 10% citric acid solution, and extracted with 3 portions of methylene chloride. The organic phases are washed with water and brine, dried over Na2SO4 and concentrated by evaporation: tRet (I)=14.5 min.

Provenance & Evidence