合成路线图解说明: N-Boc-O-benzyltyrosine (I) was converted to the aminoalcohol derivative (III) via conversion to the mixed anhydride (II) with isobutyl chloroformate and subsequent reduction with NaBH4. Acid cleavage of the N-Boc protecting group of (III) gave the free amine (IV), which was acylated with oleoyl chloride (V) to afford amide (VI). Phosphitylation of (VI) with N,N-diisopropyl di-tert-butyl phosphoroamidite in the presence of tetrazole, followed by oxidation of the intermediate phosphite with hydrogen peroxide, furnished the phosphate (VII). The tert-butyl phosphate ester groups of (VII) were finally cleaved by treatment with trifluoroacetic acid. |