2,6-Lutidine → (S)-tert-butyl (1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

A mixture of (S)-tert-butyl (4-methyl-1-((6-methyl-5-oxo-9-vinyl-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (300 mg, 0.664 mmol) (prepared as described in Example 46, Part A) osmium tetroxide (2.5% in 2-methyl-2-propanol) (4.17 μl, 0.013 mmol), and 2,6-dimethylpyridine (0.155 mL, 1.329 mmol) in 1,4-dioxane (5 mL) and water (2 mL), cooled to 0° C., was stirred for 15 min. Sodium metaperiodate (568 mg, 2.66 mmol) was added and the reaction was warmed to room temperature and stirred for 2 h. The reaction mixture was filtered through diatomaceous earth (Celite®), eluting with EtOAc. The EtOAc layer was washed with saturated aqueous NaHCO3, H2O, then brine. The organic layer was dried with Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography (EtOAc/petroleum ether) to afford (S)-tert-butyl (1-((9-formyl-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)-4-methylpentan-2-yl)carbamate (160 mg, 0.353 mmol, 53% yield) as a gummy solid. LC/MS (ESI) m/e 454.1, [(M+H)+, calcd for C25H32N3O5, 454.2].

Provenance & Evidence