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<4S-(4α,12aα)>-9-(L-leucylglycylamino)-4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide[ No CAS ]
((S)-1-[((5R,5aR,6S,6aR,7S,10aS)-9-Carbamoyl-7-dimethylamino-1,6,8,10a,11-pentahydroxy-5-methyl-10,12-dioxo-5,5a,6,6a,7,10,10a,12-octahydro-naphthacen-2-ylcarbamoyl)-methyl]-carbamoyl}-3-methyl-butyl)-carbamic acid 9H-fluoren-9-ylmethyl ester[ No CAS ]
H-GF-OH will be dissolved in methanol followed by the addition of pyridine. FmocOSu will be added to the reaction mixture and stirred overnight. The reaction mixture will be concentrated under vacuum followed by trituration with diethyl ether. This will be purified by column chromatography (silica gel) using ethyl acetate (EtOAc) and methanol as eluent. The fractions containing Fmoc-GF-OH will be concentrated and used in subsequent reaction without thrther purification. H-EG-OH will be dissolved in methanol and cooled to 0 C. followed by the addition of 50C12. The reaction mixture will be refluxed followed by the removal of solvent under vacuum. The product will be redissolved in toluene and concentrated under vacuum to remove traces of methanol and 50C12. The solid (EGOMe) will be dissolved in EtOAc and Fmoc-GF-OH will be added to it followed by the addition of DIPEA and HOP and stirred overnight. The solvent will be removed under vacuum and washed with H20 and extracted with EtOAc. The product will be purified by column chromatography (silica gel, eluent EtOAc:methanol; 9:1 v/v). The fraction containing Fmoc-GFEG-OMe will be concentrated under vacuum. Fmoc-GFEG-OMe will be dissolved in methanol and aqueous iN NaOH will be added dropwise at room temperature and stirred for 6 hours. The reaction mixture will be concentrated to 50% the volume and the pH of the solution will be adjusted to pH 3. The precipitate will be extracted with EtOAc. The EtOAc layer will be concentrated to give FmocGFEG-OH. The product will be identified by mass spectrometry. Fmoc-GFEG-OH will be dissolved in DMF (anhydrous) and cooled in an ice bath to -15 C., an excess of DCC solution will be added dropwise with constant stirring followed by an excess of p-nitrophenol (ONp) solution. The reaction mixture will be stirred for 3 hat-i 5C., followed by overnight at 4 C. and an additional 24 hat room temperature. Trace amounts of acetic acid (glacial) will be added to the solution to react with excess DCC. The precipitated byproduct DCU will be removed and the filtrate concentrated to obtain the product (Fmoc-GFEG-ONp). Recrystallization will be done from EtOH/H20 1:1 (v/v). Fmoc-GFEG-ONp will be dissolved in DCM followed by the addition of bocethylenediamine and TEA. The reaction mixture will be stirred and then concentrated followed by purification by colunm chromatography (silica gel, eluent EtOAc). The fractions containing Fmoc-GFEG-ED-Hoc was concentrated and analyzed by mass spectroscopy.