Reaktion #53986

Reaktionsgleichung

sodium carbonate

[2-hydroxy-3-methyl-1-(3-oxo-propylcarbamoyl)-butyl]-carbamic acid benzyl ester

tert-butyl (2S,3R)-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

sodium triacetoxyborohydride

→

tert-butyl (5S,12S)-12-[(R)-[(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-hydroxy-2-methylpropyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oate

Ausbeute 60.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe aqueous layer was extracted with ethyl acetate (3×75 mL)
2. 2
   WaschenThe combined extracts were washed with saturated sodium chloride solution
3. 3
   Trocknendried over sodium sulfate
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated in vacuo
6. 6
   SonstigeThe residue was chromatographed (flash column, silica gel, 2.5% methanol in methylene chloride)

Vorschrift

A solution of [2-hydroxy-3-methyl-1-(3-oxo-propylcarbamoyl)-butyl]-carbamic acid benzyl ester (175 mg, 0.519 mmol, obtained from Reference Example 14) and tert-butyl (2S,3R)-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 (300 mg, 0.416 mmol, obtained from Reference Example 6) in anhydrous tetrahydrofuran was stirred at room temperature under a nitrogen atmosphere for 15 minutes. Acetic acid (3 drops) and sodium triacetoxyborohydride (176 mg, 0.831 mmol) were added and the resulting solution was stirred under nitrogen for an additional 2.5 hours. The reaction mixture was basified to pH 9 with aqueous sodium carbonate solution, and the aqueous layer was extracted with ethyl acetate (3×75 mL). The combined extracts were washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo. The residue was chromatographed (flash column, silica gel, 2.5% methanol in methylene chloride) to provide tert-butyl (5S,12S)-12-[(R)-[(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-hydroxy-2-methylpropyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oate (258 mg, 60%) as a white amorphous solid.

Quelle