m-Chloroperbenzoic acid → (1S,3R)-1-((1S)-1-{[(2S)-2-(3-{[6-(1-{[bis(benzyloxy)phosphoryl]oxy}-1-methylethyl)pyridin-2-yl]methyl}-2-oxoimidazolidin-1-yl)-3,3-dimethylbutanoyl]amino}-2-phenylethyl)-3-{[N-(methoxycarbonyl)-3-methyl-L-valyl]amino}-4-(4-pyridin-2-ylphenyl)butyl tert-butyl carbonate

Participants

Reaction Conditions

Reaction Steps

A solution of the compound of Example 194A (1.16 mmol), dibenzyl diethylphosphoramidite (1.25 mL, 4.17 mmol), and 1H-tetrazole (0.40 g, 5.71 mmol) in tetrahydrofuran (11.0 mL) was stirred at room temperature for 12 hours. Dichloromethane (11.0 mL) was added and the mixture was cooled to −45° C., followed by addition of m-chloroperbenzoic acid (1.15 g, 6.66 mmol). After stirring for 1 hour at −45° C., the reaction was diluted with ethyl acetate and washed twice with 10% Na2CO3 and then with brine. The organic phase was dried over MgSO4, filtered and evaporated. The residue was purified by chromatography on silica gel, eluting with a gradient starting with dichloromethane and ending with 75% ethyl acetate in dichloromethane, to give the title compound (0.684 g, 48% yield over two steps).

Provenance & Evidence