Imidazole → 5(S)-(Boc-amino)-4(S)-(tert-butyldimethylsilyloxy)-6-(p-benzyloxyphenyl)-2(R)-(phenylmethyl)-hexanoic acid

Participants

Reaction Steps

Analogously to Example 1j), 1.04 g (2.00 mmol) of 5(S)-(Boc-amino)-4(S)-hydroxy-6-(p-benzyloxyphenyl)-2(R)-(phenylmethyl)-hexanoic acid in 7 ml of DMF are silylated with 1.39 g (9.0 mmol) of tert-butyldimethylchlorosilane and 1.12 g (16.4 mmol) of imidazole. Hydrolysis of the silyl ester function with 1.6 g of potassium carbonate in 46 ml of methanol/THF/water 3:1:1 and column chromatography (SiO2, hexane/ethyl acetate 4:1→2:1→1:2) of the crude product yields the title compound: TLC Rf (A)=0.69.

Provenance & Evidence