Sodium triacetoxyborohydride → tert-butyl (5S,12S)-12-[(S)-[(3R,4R,5R)-3,4-bis{[tert-butyl(dimethyl)silyl]oxy}-5-(3-(4-methoxybenzyl)-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)tetrahydro-2-furanyl](hydroxy)methyl]-5-[(1S)-1-hydroxyethyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oate

Beteiligte Stoffe

Reaktionsschritte

By using an analogous procedure to that described in Example 1, a solution of [(1S,2S)-2-hydroxy-1-(3-oxo-propylcarbamoyl)-propyl]-carbamic acid benzyl ester (99 mg, 0.32 mmol, obtained from Reference Example 18), tert-butyl (2S,3S)-2-amino-3-[(2R,3R,4R,5R)-3,4-bis{[tert-butyl-(dimethyl)silyl]oxy}-5-(3-(4-methoxybenzyl)-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)-tetrahydro-2-furanyl]-3-hydroxypropanoate (165 mg, 0.229 mmol, obtained from Reference example 5), acetic acid (4 drops) and sodium triacetoxyborohydride (97 mg, 0.457 mmol) in anhydrous tetrahydrofuran (4 ml) was stirred at room temperature under nitrogen for 4 hours. The residue was chromatographed (flash column, silica gel, 5% methanol in methylene chloride) to provide tert-butyl (5S,12S)-12-[(S)-[(3R,4R,5R)-3,4-bis{[tert-butyl(dimethyl)silyl]oxy}-5-(3-(4-methoxybenzyl)-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)tetrahydro-2-furanyl](hydroxy)methyl]-5-[(1S)-1-hydroxyethyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oate (77 mg, 33%) as a white amorphous solid.

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