Imidazole → 5(S)-(Boc-Amino)-4(S)-(tert-butyldimethylsilyloxy)-6-cyclohexyl-2(R)-[(4-benzyloxyphenyl)methyl]hexanoic acid

Participants

Reaction Steps

In analogy with Example 1 j), 28.8 g (54.8 mmol) of 5(S)-(Boc-amino)-4(S)-hydroxy-6-cyclohexyl-2(R)-[(4-benzyloxyphenyl)methyl]hexanoic acid in 288 ml of DMF, are converted into the title compound with 35.8 g (237.6 mmol) of tert-butyldimethylchlorosilane and 30 g (440 mmol) of imidazole. The title compound is purified by column chromatography (SiO2, hexane/ethyl acetate: 4:1 to 1:1); TLC Rf (E)=0.34; tRet (gradient from 75 to 100% (a) in (b) over 20 min)=25.06 min; FAB-MS (M+H+)=526.

Provenance & Evidence