反应详情

In an analogous manner to that described in Example 9, 635 mg (1.78 mmol) of t-butyl [(4S,5S)-4-(cyclohexylmethyl)-5-(S)-2-isopropyl-4-(pivaloyloxy)butyl]-2,2-dimethyl-3-oxazolidinecarboxylate are treated with trifluoroacetic acid/water/methylene chloride for the cleavage of the Boc protecting group with simultaneous opening of the oxazolidine ring and the resulting 347 mg (76%) of (3S,5S,6S)-6-amino-7-cyclohexyl-5-hydroxy-3-isopropylheptyl pivaloate are reacted without further purification with Boc-Phe-His-OH, whereby there are obtained 280 mg (37%) of t-butyl [(S)-α-[[(RS)-1-[[(1S,2S,4S)-1-(cyclohexylmethyl)-2-hydroxy-4-isopropyl-6-(pivaloyloxy)hexyl]carbamoyl]-2-imidazole-4-ylethyl]carbamoyl]phenethyl]carbamate as an amorphous solid, MS: 740 (M+H)+.